Everybody wants the best solar battery in Ghana.There are certain specifications you should use when evaluating your solar battery options, such as how long the solar battery will last or how much power it can provide. Below, learn about all of the criteria that you should use to compare your home energy storage options, as well as the different types of solar batteries.

LITHIUM VS AGM Ghana

freedom won lithium-ion battery installed in Accra,Ghana

How to compare your solar storage options

As you consider your solar-plus-storage options, you’ll come across a lot of complicated product specifications. The most important ones to use during your evaluation are the battery’s capacity & power ratings, depth of discharge (DoD), round-trip efficiency, warranty, and manufacturer.

Capacity & power

Capacity is the total amount of electricity that a solar battery can store, measured in kilowatt-hours (kWh). Most home solar batteries are designed to be “stackable,” which means that you can include multiple batteries with your solar-plus-storage system to get extra capacity.

While capacity tells you how big your battery is, it doesn’t tell you how much electricity a battery can provide at a given moment. To get the full picture, you also need to consider the battery’s power rating. In the context of solar batteries, a power rating is the amount of electricity that a battery can deliver at one time. It is measured in kilowatts (kW).

A battery with a high capacity and a low power rating would deliver a low amount of electricity (enough to run a few crucial appliances) for a long time. A battery with low capacity and a high power rating could run your entire home, but only for a few hours.

Depth of discharge (DoD)

lithium vs AGM ,DEPTH OF DISCHARGE GRAPH,GhanaMost solar batteries need to retain some charge at all times due to their chemical composition. If you use 100 percent of a battery’s charge, its useful life will be significantly shortened.

The depth of discharge (DoD) of a battery refers to the amount of a battery’s capacity that has been used. Most manufacturers will specify a maximum DoD for optimal performance. For example, if a 10 kWh battery has a DoD of 90 percent, you shouldn’t use more than 9 kWh of the battery before recharging it. Generally speaking, a higher DoD means you will be able to utilize more of your battery’s capacity.This has always been an issue in Ghana .Most people have erroneous impression that batteries need to be completely drained for batter performance.

Round-trip efficiency

A battery’s round-trip efficiency represents the amount of energy that can be used as a percentage of the amount of energy that it took to store it. For example, if you feed five kWh of electricity into your battery and can only get four kWh of useful electricity back, the battery has 80 percent round-trip efficiency (4 kWh / 5 kWh = 80%). Generally speaking, a higher round-trip efficiency means you will get more economic value out of your battery.

Battery life & warranty

For most uses of home energy storage, your battery will “cycle” (charge and drain) daily. The battery’s ability to hold a charge will gradually decrease the more you use it. In this way, solar batteries are like the battery in your cell phone – you charge your phone each night to use it during the day, and as your phone gets older you’ll start to notice that the battery isn’t holding as much of a charge as it did when it was new.

Your solar battery will have a warranty that guarantees a certain number of cycles and/or years of useful life. Because battery performance naturally degrades over time, most manufacturers will also guarantee that the battery keeps a certain amount of its capacity over the course of the warranty. Therefore, the simple answer to the question “how long will my solar battery last?” is that it depends on the brand of battery you buy and and how much capacity it will lose over time.

For example, a battery might be warrantied for 5,000 cycles or 10 years at 70 percent of its original capacity. This means that at the end of the warranty, the battery will have lost no more than 30 percent of its original ability to store energy.

Manufacturer

Many different types of organizations are developing and manufacturing solar battery products, from automotive companies to tech startups. While a major automotive company entering the energy storage market likely has a longer history of product manufacturing, they may not offer the most revolutionary technology. By contrast, a tech startup might have a brand-new high-performing technology, but less of a track record to prove the battery’s long-term functionality.

Whether you choose a battery manufactured by a cutting-edge startup or a manufacturer with a long history depends on your priorities. Evaluating the warranties associated with each product can give you additional guidance as you make your decision.

LITHIUM VS AGM, Ghana

Victron Energy AGM super cycle batteries installation in Accra

Automotive companies are jumping on the energy storage bandwagon

Home energy storage technology and electric vehicles are a lot alike: they both use advanced batteries to create more efficient, sustainable products that can reduce greenhouse gas emissions.

As electric vehicles become more popular, more companies are dedicating significant research and development funds to developing batteries, and they’re expanding into the energy storage business. Tesla is the first mainstream example (with their Powerwall battery), but Mercedes-Benz and BMW are also bringing standalone batteries to the market in 2017.

How long do solar batteries last?

There are two ways to answer this question and the first is to determine how long a solar battery can power your home. In many cases, a fully charged battery can run your home overnight when your solar panels are not producing energy. To make a more exact calculation, you’ll need to know a few variables, including how much energy your household consumes in a given day, what the capacity and power rating is for your solar battery and whether or not you are connected to the electric grid.

For the sake of a simple example, we’ll determine the size of a battery needed to provide an adequate solar plus storage solution with national average data from our research at Nocheski Solar. The average Ghana household will use roughly 15 kilowatt-hours (kWh) of energy per day and a typical solar battery can deliver some 5 kWh of capacity. Thus a very simple answer would be, if you purchased three solar batteries, you could run your home for an entire day with nothing but battery support.

In reality, the answer is more complicated than that. You will also be generating power with your solar panel system during the day which will offer strong power for some 6-7 hours of the day during peak sunlight hours. On the other end, most batteries cannot run at maximum capacity and generally peak at a 90% DoD (as explained above). As a result, your 5 kWh battery likely has a useful capacity of 4.5 kWh.

Ultimately, if you are pairing your battery with a solar PV array, one or two batteries can provide sufficient power during nighttime when your panels are not producing. However, without a renewable energy solution, you may need 3 batteries or more to power your entire home for 24 hours. Additionally, if you are installing home energy storage in order to disconnect from the electric grid, you should install a few days’ worth of backup power to account for days where you might have cloudy weather.

 

Solar battery lifespan

The general range for a solar battery’s useful lifespan is between 5 and 15 years. If you install a solar battery today, you will likely need to replace it at least once to match the 25 to 30 year lifespan of your PV system. However, just as the lifespan of solar panels has increased significantly in the past decade, it is expected that solar batteries will follow suit as the market for energy storage solutions grows.

Proper maintenance can also have a significant effect on your solar battery’s lifespan. Solar batteries are significantly impacted by temperature, so protecting your battery from freezing or sweltering temperatures can increase its useful life. When a PV battery drops below -1.1 ° C, it will require more voltage to reach maximum charge; when that same battery rises above the 32.22 ° C threshold, it will become overheated and require a reduction in charge. To solve this problem, many leading battery manufacturers, like Tesla, provide temperature moderation as a feature. However, if the battery that you buy does not, you will need to consider other solutions like earth-sheltered enclosures. Quality maintenance efforts can definitely impact how long your solar battery will last. Temperatures in Ghana range between 25-35 deg Celsius.

What are the best batteries for solar?

Batteries used in home energy storage typically are made with one of three chemical compositions: lead acid, lithium ion, and saltwater. In most cases, lithium ion batteries are the best option for a solar panel system, though other battery types can be more affordable. Order you Lithium batteries in Ghana here

  1. Lead acid

    Lead acid batteries are a tested technology that has been used in off-grid energy systems for decades. While they have a relatively short life and lower DoD than other battery types, they are also one of the least expensive options currently on the market in the home energy storage sector. For homeowners who want to go off the grid and need to install lots of energy storage, lead acid can be a good option.This is the most common solar battery type in Ghana.

  2. Lithium ion

    The majority of new home energy storage technologies, such as the , use some form of lithium ion chemical composition. Lithium ion batteries are lighter and more compact than lead acid batteries. They also have a higher DoD and longer lifespan when compared to lead acid batteries.  However, lithium ion batteries are more expensive than their lead acid counterparts.This is the least common solar battery type in Ghana

  3. Saltwater

    A newcomer in the home energy storage industry is the saltwater battery. Unlike other home energy storage options, saltwater batteries don’t contain heavy metals, relying instead on saltwater electrolytes. While batteries that use heavy metals, including lead acid and lithium ion batteries, need to be disposed of with special processes, a saltwater battery can be easily recycled. However, as a new technology, saltwater batteries are relatively untested, and the one company that makes solar batteries for home use (Aquion) filed for bankruptcy in 2017.This battery type is virtually non existent in Ghana.


Solar Power ,energy excitement in Nigeria.The market at Sabon Gari in Kano state, Nigeria, has 12,000 shops where you can buy everything from vegetables to visual arts. It’s so big they call it ‘Mini Africa’. Several kilometres of bustling passageways and roads, packed with shoppers and the shouts of traders calling attention to their bargains, makes for an exhilarating atmosphere …you simply can’t visit Nigeria and not go there!

Solar energy POWER excitement in Nigeria World recognition for huge Solar-Powered Market 8

© Alexander Kohler, Source Persistent Energy

However until recently there’s been something else in the atmosphere, too: quite a lot of smoke!

Noise and fumes

Grid electricity supply problems resulted in 72% of the shops which needed electricity deciding to generate their own power using petrol and diesel generators – a survey found. Apart from the pollution and the noise, the market regularly experienced destructive fires causing damage estimated in the millions of Naira.

Solar power, energy excitement in Nigeria World recognition for huge Solar-Powered Market

© Alexander Kohler, Source Persistent Energy

To address this and similar issues, The Federal Government of Nigeria, through the Rural Electrification Agency launched Energising Economies Initiative (EEI), to focus on building a reliable energy infrastructure at markets and other economic hubs – together with private developers.

Solar power energy excitement in Nigeria World recognition for huge Solar-Powered Market 5

His excellency the Vice President of Nigeria, Yemi Osinbajo accompanied by REA CEO/MD Damilola Ogunbiyi conducting inspection of one of the energy hubs at Sabon Gari.

 

His excellency the Vice President of Nigeria, Yemi Osinbajo accompanied by REA CEO/MD Damilola Ogunbiyi conducting inspection of one of the energy hubs at Sabon Gari.

Survey, design, install

The Nigerian based off-grid energy specialist Rensource – who aims to build West Africa’s largest portfolio of electricity micro-grid utilities using best-in-class technologies – were asked to carry out the installation.

Rensource recruited and trained 100 engineers, administrative staff, and craftsmen. Like so many countries, Nigeria has a large jobless population – new recruits were drawn from amongst Nigeria’s unemployed.

The first goal was to win the confidence of market stall holders that reliable power provision could be a reality – it was something no one had experienced before. A ‘needs’ survey provided the team with information essential to their system design …some shops needing only lighting; others had  air-conditioning and refrigeration units.

Solar power energy excitement in Nigeria World recognition for huge Solar-Powered Market 2 

How was it achieved

Working from survey results, a colossal 1.6MWh bank of Lithium-iron Phosphate batteries from hybrid battery manufacturer and technology partner BOS AG, based in Germany was selected as the power storage solution. The power installation was zoned into 160 10kWh systems – each providing power for between 60 and 80 shops.

Solar power energy excitement in Nigeria World recognition for huge Solar-Powered Market 3

800kVA of power is made available using 160 Victron MultiPlus inverter/chargers. These inverters have a peak power capability equal to double their continuous output – which ensures smooth power supply even as air conditioning units, for example, cycle on-and-off.  320 Blue solar MPPTs 150/70 units harvest the power from a 1.6MWp solar array, optimising the charge current to the Lithium iron battery bank.

Solar energy excitement in Nigeria World recognition for huge Solar-Powered Market 6

The system allows for future expansion – which is just as well because business is booming and demand for power is growing.

This clean electricity – made affordable by smart meters – brings only benefits it seems: Whereas the price of generator-produced electricity was around 1000 Naira per day, smart energy has brought that cost down to 116 Naira, typically.

International recognition

The success of this huge project has received deserved international recognition – Rensource won the Excellence in Climate Solutions award at the Transformational Business Awards ceremony (also known as ‘the Oscars of the renewables world’) which was held in June 2019, hosted by The International Finance Corporation (World Bank Group and Financial Times.

Since the completion of this project, four more markets now benefit from renewable electricity with a further fourteen scheduled. These developments are bringing welcome employment and training to enthusiastic young people who are really enjoying being involved with such a worthwhile scheme.

Rensource team after the inauguration ceremony! This project helped create many jobs for the youth of Nigeria.

Veeresh Anehosur of BOS AG says: The key to these mini grids and micro utility projects is that they need to be commercially attractive and sustainable in long-term. This is possible only if the technology works flawlessly over the years. ‘Low’ or ‘No’ system downtime and good system-level performance helps win customer confidence in the project – which decreases non-payment risk …a perfect scenario to recoup the initial investment. How do you ensure an efficient and cost-effective mini grid over time? One key element is to include lithium. Lithium has one of the least LCOE [Levelized Costs of Energy] compared to Lead acid. For projects where an initial low-capital investment is critical, a combination of Lead acid and Lithium can be used which gives a cost-effective high-performance solution.

Let’s have a look around the market, and hear how market traders are getting on with their new clean power:


How the Digital Inverter Compressor Has Transformed the Modern Fridge.For decades, Refrigerators or Fridges  had single-speed compressors that were always either off or on. A compressor is the engine that powers the refrigeration cycle, moving refrigerant through the inner and outer heat exchange pipes. With a single-speed compressor, when the temperature inside the fridge reaches above a certain temperature, the compressor suddenly switches on – a noise almost everyone is familiar with. The single-speed compressor operates at full power, producing enough cool air until the temperature has sufficiently decreased before abruptly shutting off.

Enter the digital inverter compressor (a compressor that can operate at variable speeds because it is operated with a digital inverter). Unlike the standard single-speed compressor, which is either off or operating at full speed (typically about 3,600rpm), the digital inverter compressor is almost always on, but can operate at different speeds – from 1,100 to 4,300rpm. This ensures high efficiency and consistent temperature inside the refrigerator. It also results in significant cost savings, a reduced carbon footprint, less noise and a longer lifespan for the compressor. The digital inverter compressor is one of the most important innovations in the history of Fridges and food preservation and Samsung has led the way.

Today, digital inverter compressors are the main technology used in Samsung’s signature appliances eg, air conditioners, washing machine & Fridges, including those that are part of the Chef Collection, the T9000, as well as food showcases and large-capacity premium Fridges. This has played no small role in Samsung’s ascent to become the world’s top refrigerator manufacturer.

In addition, Samsung has become a technical leader, as one of the world’s top manufacturers of this game-changing technology. Samsung produced more than 40% of the world’s digital inverter compressors in 2014 as other major manufacturers now use Samsung’s superior compressors in their Fridges.

Samsung really began its rise in this area in 1999 when the company pushed investment in BLDC (brushless direct current) inverter compressors. Since then, Samsung has continued to expand its investment in research and development, hiring a highly skilled team of researchers, which has enabled the company to remain on the cutting edge of technology. From 2000 to 2014, Samsung sold a total of 27.5 million BLDC inverter compressors, which are highly efficient and less noisy compared to a single-speed induction motor compressor. BLDC motors are also better in terms of reliability and longevity. The current Chef Collection refrigerator employs a fifth generation technology of BLDC inverter compressor.

The benefits are obvious. A fridge with a Samsung digital inverter compressor consumes up to 46.9% less energy than a single-speed induction motor compressor, and thus contributes far less in the way of greenhouse gases. Because the digital inverter compressor gradually speeds up and slows down, it does not have to work as hard to manage the temperature. This means that Fridges with digital inverter compressors suffer less wear and tear on components and are therefore far more durable than fridges with conventional compressors. This has allowed Samsung to offer a 10-year warranty on its digital inverter compressors.

The lack of abrupt starts and stops means no sudden, potentially startling disruptive noises interrupting your dinner. Digital inverter compressors are also far less noisy overall: up to 3 decibels quieter. And the consistent, uniform cooling that maintains the desired temperature means food lasts longer because changes in temperature can lead produce, meat, fish and dairy to spoil more quickly. It all means that consumers will save money on both their electric bills and food costs.

When Samsung sought input from its highly influential group of culinary experts, also known as the Club des Chefs, they emphasized that temperature uniformity is a crucial component of any fridge that may be used in a Michelin-starred kitchen. Chef Collection Fridges boast “Chef Mode,” which ensures that the temperature fluctuates no more than plus or minus 0.5 degrees celsius. The Chef Collection refrigerator is equipped with three evaporators and two compressors to control humidity. It is also made of stainless steel panels, which help to keep the temperature consistent.

These Digital Inverter technology based appliances are best used with solar power options for 2-5 bedroom homes from Nocheski


EnGo – Smart Solar Street light pole is made by   EnGoPlanet ,the  sustainable solar lighting experts   recently launched a stylish new street light pole product which can even be retrofitted.The attachable design is of a solar cylinder module which can be quickly and easily mounted on any suitable pole for easy installation and disassembly.

Using 6 slim solar panels, with a solar cell efficiency of up to 21.2%, fixed to a hexagonal frame, ensures that half of them will face sun light at any time of the day.

The off-vertical cluster arrangement of the panels makes them less vulnerable to high-winds, less likely to accumulated dust and grime, and easier to clean.

The energy is harvested by a Victron SmartSolar MPPT 75-15. Bluetooth enabled, SmartSolar MPPTs include features which protect the battery from being too deeply drained, and have intelligent dynamic charge algorithms which work with the seasons to ensure the battery will at least periodically be returned to 100% charge.

EnGoPlanet use their own high-quality Lithium batteries, making the unit suitable for off-grid applications where night lighting is required. EnGo – Smart Solar Street light pole can also be used where a grid connection is present – in which case the units will run from their own batteries except where long-continued spells of poor weather require a power supplement to be drawn from the grid. This option is recommended for locations which are often cloudy, or shaded.

Alternatively, grid connected poles can be supplied without battery. Energy produced by the panels will be sent directly to the grid. Savings of up to 80% are possible.

EnGo – Smart Solar Street light pole  installations are also able to collect valuable environmental data which can be interrogated online. Other applications for the poles are for uses such as CCTV, sensors, wifi hotspots, and even phone charging points.

At Nocheski, we  look forward to installing  EnGo – Smart Solar Street light pole  soon

Justin Tyers


Victron Energy CANvu GX …information you can touch! It’s so convenient to be able access all your system information via touch screen – and because the Victron Energy GX is a sealed-unit, you can install it in some challenging environments!

P67 rating of the Victron Energy  CANvu GX means that it is completely protected against dust ingress, and can even withstand half an hour’s immersion in water 1 metre deep!

The Victron Energy CANvu GX is the latest addition to the Venus family – the information gateway which allows you to set-up, monitor and manage all the component parts of your private energy installation. In exactly the same way as you use the CCGXVenus GX; and Octo GX – the Victron Energy CANvu GX gathers data from your Inverter/ChargerBattery MonitorSolar Charge Controller, and batteries to allow optimal communication between components, maximising battery-charging and solar harvest.

And, of course, it allows you to interrogate the status of each device. But amongst the whole family, it is the Victron Energy CANvu GX which is ideal when the information is required to be displayed outdoors, or in difficult environments.

The arrival of the Victron Energy CANvu GX will be welcomed particularly by those users who work in the open. It is entirely at home on board vessels at sea, or on building sites – in applications such as the control panel of Hybrid Generators. It is also ideal in factories where industrial processes are wet, or dusty.


The unit comes with a dash/fascia mounting kit:


Please note that in order to operate the Victron Energy  CANvu GX you will need an IO Extender and wiring kit, and that this must be ordered separately:

The full colour screen of the Victron Energy  CANvu GX will be familiar both in appearance and size to anyone who has seen or used the CCGX. The system offers 3 VE.Direct ports and one USB port; a second, separate CAN-bus port; and it can receive digital inputs. It doesn’t have a buzzer. WiFi is not built-in, but a USB WiFi dongle can be attached. A comparison of features between all members of the GX family can be found here.

Justin Tyers


Lithium-ion vs AGM Battery has been a very popular topic in independent power circles in recent times In light of my last post concerning the use of the DC or Hybrid concept for electrical power, it occurred to me that the system could also have used monobloc AGM/Gel batteries or indeed a bank of long life 2 volt gel cells. In that case why was Lithium chosen? Hopefully this post may go some way to highlighting that decision process.

Across all markets over recent years Lithium-ion batteries have been gaining in traction . To the uninitiated it is easy to dismiss Lithium-ion as an expensive alternative to VRLA (valve regulated lead acid) technologies such as AGM (absorbed glass mat), if simply looking at the amp-hour (Ah) rating. This was the initial mistake I made a few years back. Digging deeper it became clear to me that there is a lot more than Ah ratings to consider, when choosing the best batteries for your application.Lithium-ion vs AGM Battery

In the marine world (which is where I have the most experience) the choice these days and especially with higher loads – often simply comes down to Lithium-ion vs AGM Battery. In the comparisons below whilst Gel batteries are shown, they do have a lower effective capacity at high discharge currents.  They cost about the same as AGMs, assuming both types are monoblocs, as opposed to 2 V long life gel cells. Wet cell or flooded lead acid (FLA) batteries whilst referred to are not considered for the crux of this particular comparison, primarily due to maintenance and safety considerations in the marine environment. This of course may not apply to other markets.Lithium-ion vs AGM Battery

Useable energy and cost

It is generally accepted that the most economic and practical depth of discharge (DOD) for an AGM battery is 50%. For Lithium-iron-phosphate (LiFePO4 or LFP) which is the safest of the mainstream Li-ion battery types, 80% DOD is used.

How does this work out in the real world? Let’s take two Victron 24V battery examples and compare useable energy for a small yacht:

  • 1 x Victron Lithium-ion 24 V 180 Ah

The nominal voltage of the LFP cell is 3.3 V. This 26.4 V LFP battery consists of 8 cells connected in series with a 180 Ah rating. The available energy is 26.4 x 180 = 4. 75 kWh. Useable energy is 26.4 x 180 x 0.80 = 3.8 kWh.

  • 2 x Victron AGM 12 V 220 Ah

The nominal voltage of the lead-acid cell is 2.0 V/cell. Each 12 V monobloc battery consists of 6 cells connected in series with a 220 Ah rating. Connecting 2 x 12 V 220 Ah batteries in series to give 24V and 220 Ah, the available energy is 24.0 x 220 = 5.28 kWh. Useable energy is 24 x 220 x 0.50 = 2.64 kWh.

This begs the question, what Ah rating of AGM batteries would be the equivalent of the 3.8 kWh useable energy of the Lithium-ion battery? To get 3.8 kWh of useable energy from an AGM battery it would need to be twice that size to start with due to the 50% DOD economy rule i.e. 3.8 x 2 = 7.6 kWh. At 24V that would mean 7,600/24 which gives us a battery rating of 316.66 Ah, which is moving closer to twice the rated capacity of the Lithium-ion 24 V 180 Ah. Note this does not take into account, the ageing of the batteries, temperature derating or the effect of higher loads. For AGM batteries, higher loads have a greater effect than on Lithium. See the section – Useable energy: effect on discharge capacity and voltage with differing loads, below. Based on all this it is reasonable to say that an AGM battery will need to be twice the Ah rating of a Lithium one.

What about price? Using the Victron price list we see that a 12V 220 Ah AGM is € 470 ex VAT or 2.136 €/ Ah. For 316.66 Ah that is the equivalent of € 676.50 at 12V or € 1,353 at 24 V. The 24V 180 Ah Lithium is € 4,704 for the same amount of useable energy and is therefore 4,704/1,353  = 3.48 times more expensive (or less if we consider the factor of 2 referred to above) when comparing Ah ratings.

 

Based on this you might immediately conclude that Lithium is not cost effective, however useable energy compared to price is only part of the story.Lithium-ion vs AGM Battery

Usable energy

 

Weight

Most Ah ratings of batteries regardless of type are specified at the 20 hour rate. This was fine in the days of light loads, but as the number of loads and the size of loads has increased over time, we also need to look at high short term loads, medium and longer term ones for differing types of equipment. This can mean a large battery pack. At the extremes we might have air conditioning running for 10 hours using 10 kW, compared to an LED light using 100 Watts in that time. Balancing these differing requirements and all the loads inbetween becomes key. With a large pack as shown below to achieve this, it becomes clear just how heavy Lead Acid can be compared to Lithium. 1360/336 = 4 times heavier.

Weight

 

Useable energy: effect on discharge capacity and voltage with differing loads

As stated earlier most batteries Ah rating are quoted at the 20 hr rate. In the image below for the lead acid battery, if that were a 100 Ah battery at the 20 hr rate, you can see that 0.05C means 100 x 0.05 = 5 Amps for 20 hours = 100 Ah available until the battery is totally flat. As we use only 50% of the battery we can see that the voltage will still be 24 V at 50% DOD for a 5 Amp load over 10 hours, and therefore we would have consumed 50 Ah.

Increasing the current draw (as the graphs below show) can affect the useable energy available and battery voltage. This effective shrinkage in the rating is known as Peukert’s effect. With lead acid the higher the load, the more you need to increase the Ah capacity of your battery to help alleviate this. With Lithium however a load  of even 10 times greater at 0.5C can still have a terminal voltage of 24V at 80% DOD/20% SOC, without going up on the Ah rating of the battery. This is what makes Lithium particularly suitable for high loads.

Note: In the graphs below Discharge Capacity vs Terminal Voltage is shown. Usually you will see AGM graphs as Discharge Time vs Terminal Voltage. The reason we plot Discharge Capacity (instead of Discharge Time) is that Lithium has a higher and more stable terminal voltage than AGM, so plotting the curves with Discharge Capacity in mind gives a more accurate comparison of the chemistries, showing that Lithium increases useable energy at higher loads due to higher and more stable terminal voltages. Whilst you may consider this a grey area (in part too due to the varying internal resistance of batteries also) it is probably the only true way to compare the technologies. This is further demonstrated in the images below the graphs.

Lithium – Discharge Capacity vs Terminal Voltage

LithiumLead Acid – Discharge Capacity vs Terminal Voltage

Lead_Acid, Lithium-ion vs AGM BatteryUseable Energy (Lead Acid)

Useable_Energy_Lead_Acid

Useable Energy (Lithium)

Useable_Energy_Lithium Lithium-ion vs AGM Battery

 Charge Efficiency

Much that we have seen in the discharge process is also true in the converse process of charging. Don’t be put off by the large generator sizes shown below, as this blog merely shows a range of scenarios. Solutions are scalable in principal. First let’s compare charge efficiency of Lead Acid on the left to Lithium on the right, during the complete charge cycle. Charging the last 20% of a lead acid technology battery is always slow and inefficient when compared to Lithium. This is borne out in the fuel costs (or whatever charging source you use) in the images further down. Note the difference in charge times too.

Note: Charge rates

The recommended charge rate for large size AGM batteries is 0.2C  i.e. 120A for a 600A battery consisting of paralleled 200Ah blocks.

Higher charge rates will heat up the battery (temperature compensation, voltage sensing and good ventilation are absolutely needed in such a case to prevent thermal runaway), and due to internal resistance the absorption voltage will be reached when the battery is charged at only 60% or less, resulting in a longer absorption time needed to fully charge the battery.

High rate charging will therefore not substantially reduce the charging time of a lead-acid technology battery.

By comparison a 200Ah Lithium battery can be charged with up to 500A, however the recommended charge rate for maximum cycle life is 100A (0.5C) or less. Again this shows that in both discharge and charge that Lithium is superior.

Charge_Efficiency Lithium-ion vs AGM Battery


Charge_Efficiency2 Lithium-ion vs AGM Battery


 

Charge_Efficiency3 Lithium-ion vs AGM Battery

Battery choices, markets and cycle life

Depending how you treat a battery you can reasonably expect the range of cycles below, subject to the DOD and the battery banks being properly sized for the loads. Operating temperature also comes into play. The hotter the battery the less time it will last. Battery capacity also reduces with ambient temperature. The baseline for variations due to temperature is 25 degrees Centigrade.

Battery_Cycle_Life


Battery_Cycle_Life2 Lithium-ion vs AGM Battery


Battery_Cycle_Life3 Lithium-ion vs AGM Battery

 

Conclusions

Clearly AGM batteries will need to be replaced more often than Lithium. It is worth bearing this in mind as this entails time, installation and transportation costs, which further negates the higher initial capital cost of Lithium as does the lower cost of recharging Lithium.

No matter what battery choice you make there is also both a capital cost and technological risk at the outset. If you are in a position of having the capital for the higher upfront costs of Lithium, you might find that life is easier and that choice is a cost effective one over time. Much of this depends on the knowledge of the operator and how they treat a battery system. There is an old saying that batteries don’t die, they are killed. Good management practices are your insurance against early failure, regardless of the technology used.

Lithium-ion vs AGM Battery? The choice is yours. Personally I think the time is right to consider Lithium in the marine industry as a cost effective, reliable, high performance solution. Last week (it was only out of curiosity you understand) I went for a test drive in a Lithium-ion powered Tesla Model S – and as we know, no self-respecting electric vehicle manufacturer would still use lead acid based battery technologies today. Time for the marine industry to catch up with the Lithium-ion vs AGM Battery debate?

John Rushworth

Credits

Thanks to Reinout Vader and Johannes Boonstra for the images and technical advice in writing this blog.

Further reading

Whitepapers, inc Energy Unlimited by Reinout Vader:  https://www.victronenergy.com/support-and-downloads/whitepapers

Battery choices: https://www.victronenergy.com/batteries

 

 

 

 

Continue reading →


How to Choose Solar Panels in Ghana will always be a major question . This is due the the wide assortment of varieties available and the lack of expertise in this specialized area of energy.Solar panels provide renewable energy for your home, which helps the environment and reduces your electricity bill. But not all panels are alike. The material a panel is made of, what solar inverter it uses, and how it mounts to your roof determines what environments it works best in. Before you buy solar panels for your home, research the different factors and decide which option is right for you in Ghana.

Ghana has an average effective sunshine of 5.5 hours daily .As a considerable investment, it’s worth evaluating a solar power system for your home before have it installed. Doing your research and seeking professional advice can help you to make an informed decision. Here are a couple of other things to consider before making the change:

Types of Solar panels in Ghana

There are different types of solar cells, with different efficiencies. Although their names might sound confusing, it is good to know at least the name not to be out-of-topic if your supplier happens to mention this.Popular solar panel brands in Ghana include ,Jinko solar,Victron Energy,LG,Yingli and Canadian Solar.Its however important to seek the advice from a professional as there are many knock offs or  fake products on the Ghana  market.

Monocrystalline silicon offers high efficiency and good heat tolerance characteristics with a small footprint. Polycrystalline (or multi-crystalline) silicon cell based solar panels are now the most popular choice in residential installs. There are also Amorphous (or thin-film) silicon cells, which use the least amount of silicon and are not very efficient. For an equivalent wattage, a crystalline panel will be smaller than an amorphous panel.

monocrystalline solar panels in Ghana installed on a rooftop

Choose monocrystalline solar panels for efficiency. Monocrystalline solar panels are the best at converting light to energy because of their high silicon purity. That being said, monocrystalline solar panels are often the most expensive—this option is best if you want the highest productivity and price tag.

  • Monocrystalline solar panels cost between $150-350 USD per panel.
  • Monocrystalline solar panels also produce the most waste when they’re manufactured. If you’re buying solar panels to go green, another material may suit your needs better.
  • All solar panels are made of silicon. The higher the silicon purity, the better your panel will work, which is why monocrystalline solar panels in Ghana are ideal.

Go with polycrystalline solar panels for an environmentally-friendly option.Polycrystalline solar panels utilize all of the silicon material they’re manufactured with, making them the “greenest” panel option. Polycrystalline solar panels are also cheaper than monocrystalline panels, though they are not quite as efficient.

  • Polycrystalline solar panels in Ghana  usually cost between $100-250 USD per panel.
  • other school of thought claim that Polycrystalline solar panels do not do as well in warm temperatures and that Hot climates with temperatures regularly above around 80 °F (27 °C) are not suitable for polycrystalline panels.This may be true depending on the installation technique utilized.Its important to allow steady air flow underneath the solar panels to produce cooling effect.

Buy thin-film solar panels for the most budget-friendly option. Thin-film panels are cost-efficient to make and are usually the cheapest option. They also, however, degrade faster than other panels. Choose thin-film if you need a simple solar panel that may need more repairs over the years.

There is also another variation called solar cloth i.e photovoltaic textiles we have developed are as thin as bank notes and flexible enough to wrap around a pencil, which allows their use on virtually any type of surface

  • Thin film solar panels usually cost between $125-200 USD per panel.
  • Thin-film panels usually need the most space and are less practical for smaller homes. They may need up to twice as much room as a mono- or polycrystalline solar panel with the same energy output.

Buy amorphous solar panels for smaller homes

Amorphous solar panels are a subset of thin-film solar panels. Generally, they are smaller than other thin-film panels. Through a process called “stacking,” which involves multiple layers of amorphous silicon cells, these panels can reach high levels of efficiency, around twice as high as other thin-film solar panels.

  • Amorphous solar panels are more expensive than other thin-film panels.
  • Amorphous solar panels generally cost between $100-200 USD per panel.

Continue reading →


Solar Cloth:producing power from textiles everywhere .we always need to keep our eye on emerging technologies and how they may relate to our products, both now and in the future. Solar cloth is one such technology that has certainly got me excited. You can see the solar cloth panels embedded in the mainsail of the yacht above, which is ideal as deck area for conventional modules is limited on sailing yachts.

Solar cloth is not just for boats though. Yesterday I spoke to Alain Janet from solarclothsystem.com and learned that it can also be integrated into canopies, to provide power for outdoor events for example or indeed to recharge electric vehicles. Even an awning for an RV or overland 4 x 4 could probably use such a system too.

However, Alain is a sailmaker to trade and naturally it is in that field that his first system is to be deployed, with UK Sailmakers (France). The UK Sailmakers group has over 50 lofts and service centers around the world, so to my mind they are well placed to bring this technology to market.

Below is a press release, concerning these new PowerSails.

SOLAR SAILS TO POWER TRANS-ATLANTIC RACER

Defi Martinique

Frenchman Daniel Ecalard has entered his Open 50 DEFI MARTINIQUE in the 3,500-mile Route du Rhum from St. Malo, France to Guadeloupe in the Caribbean. His goal: to complete the race with zero carbon emissions. Ecalard plans to carry no diesel for generating electricity in a boat that bristles with electronics that do everything from communicating and navigating to making water and moving the boat’s canting keel.

He will use the boat as a test bed for clean energy solutions. His primary source of power will be solar panels laminated into his Titanium® mainsail to cover all the boat’s electrical needs. The sails are being made by UK Sailmakers France, which has developed the technology for solar cells that can be either laminated to new sails or affixed to existing sails. This exclusive technology is called PowerSails and is being developed by Alain Janet, owner of UK Sailmakers France.

These cutting-edge, light-weight films can generate electricity in low light and indirect sunlight. They are supple enough to handle the sail being luffed as well as folded. The panels will be put in the upper part of the main, above the third reef.

Janet says that the mainsail for DEFI MARTINIQUE is expected to produce on average 500 Watts per hour, budget allowing. Ecalard’s boat was built in 1998 for that year’s BOC race. In 2002-2003, Brad Van Liew won the 50-footer division of the 30,000-mile Alone Around Race by winning all four legs with this boat. She still holds the 24-hour distance record for a singlehanded 50-footer when she went 345 miles in a day. In 2008, she won her class in the Newport Bermuda race. In 2010 the boat starred in the Hollywood movie “Charlie St. Cloud” where Solar Cloth:producing power from textiles everywhere

Ecalard’s ultimate goal is to build a sailing freighter for working the inter-island trade in the Caribbean. For more information about this project go to: http://seafretcaraibes.fr/

Credits

Our thanks to Adam Loory of UK Sailmakers International for the interview and text above, with RDR (Route du Rhum) skipper Daniel Ecalard.

As a footnote, we also wish Alain all the best for his PowerSails project. And if there is a place for Victron to assist, then I’m sure we will as emerging markets and technologies are surely a key to business growth for all. So, if on your Victron travels you too come across something new, that is noteworthy of a post here on the Victron blog, do let us know.

John Rushworth

 


Official opening: VICTRON-Competence Centre, Klagenfurt

A little over a year ago Victron Energy in association with Austrian Victron Energy dealer E-BOX Off-Grid Power Systems, together with HTL1 Lastenstraße and their headmaster Dr. Michael Archer forged a partnership to utilise Victron Energy products for their varied educational program – to build a ‘Competence Centre’.

As a result on Thursday, 5th December 2018, the new VICTRON-Kompetenzzentrum (VICTRON-Competence Centre) for ‘Renewable Energy and Storage Technology’ was opened at the school.

HTL1 Lastenstraße is a Higher Technical Institute in Klagenfurt, southern Austria, with around 1100 students and 120 teachers. The school trains engineers in the fields of mechanical engineering, electrical engineering and mechatronics. It has around 34 workshops and laboratories as well as several competence centres. Another focus is ‘Land und Umwelttechnik’ (agricultural engineering and environmental technology).

This all makes HTL1 a unique training centre, not only for students from Carinthia but southern, eastern and western Austria. With the new VICTRON-Competence Centre training courses will specialise in the fields of energy storage technology, photovoltaics and energy management. Besides these courses Victron Energy have also been welcomed to run their own special courses at the school. In addition, interested companies will also have the opportunity to use this modern infrastructure for their own education and training events.

HTL1 Lastenstraße – The school is equipped with many different, modern photovoltaic-systems.

The school were particularly pleased to receive a visit from Victron Energy sales manager Leo Yntema  for the opening. Here’s a brief video (in German) of that visit and a few photos from the opening event.

https://youtu.be/r9wasVuZIUU

From left to right: Manfred Hartner – Managing Director of  E-BOX Off-Grid Power Systems, Dr. Michael Archer – Principal of HTL1 Lastenstraße and Leo Yntema of Victron Energy.

A student explains one of the 5 Workstations and its components at the opening.

From left to right: Andreas Albel, the teacher who is responsible for the VICTRON-Kompetenzzentrum and Leo Yntema of Victron Energy.

Equipment utilised

There are 5 workstations utilising Victron Energy equipment. Each workstation is equipped with its own separate 3kWp photovoltaic-system, plus each of the panels can be switched on and off separately.

Workstation 1: components / power storage / 3-phase
  • 3 x MultiPlus 48/3000/35-16
  • 1 x Color Control GX
  • 1 x Battery Monitor BMV-700
  • 4 x LiFePO4 battery 12.8V/90Ah – BMS
  • 1 x Battery Management System VE.Bus
Workstation 2: components / power storage / 1-phase
  • 1 x MultiPlus 48/3000/35-16
  • 1 x Color Control GX
  • 1 x Wall mount enclosure for Color Control GX
  • 1 x Battery Monitor BMV-700
Workstation 3: components / power storage / 1-phase
  • 1 x ECOmulti 24/3000/70-50 2,3 kWh LiFePO4
  • 2 x LiFePO4 battery 12.8V/90Ah – BMS
Workstation 4: Components / power storage / DC coupled
  • 1 x BlueSolar MPPT 150/85 CAN-bus
  • 1 x Wall mount enclosure for Color Control GX
  • 1 x Battery Monitor BMV-700
  • 1 x Venus GX
  • 24 x OPzV 200 Batteries
Workstation 5: Components / power storage / DC coupled
  • 1 x EasySolar 48/3000/35 MPPT 150/70 with Color Control GX built-in
  • 24 x OPzV 200 Batteries

Conclusion

It’s great to see the new VICTRON-Competence Centre now open and we trust it will serve as a valuable resource for the school and the young engineers of tomorrow.

This artcle was orriginally published on the victron blog by John Rushworth on January 31st, 2019

Links

Interview with Dr. Archer – https://www.victronenergy.com/blog/2017/11/13/back-to-school-with-victron-energy/

HTL1 Lastenstraße Klagenfurt Website – http://htl1-klagenfurt.at/index.php/en/

HTL1 Lastenstraße Klagenfurt on Facebook – https://www.facebook.com/HTL1.Klagenfurt/

E-BOX Off-Grid Power Systems Website – http://www.e-box.co.at


Siemens partners WestPark for industrial park in Takoradi

Siemens has announced it has signed a Memorandum of Understanding (MOU) with WestPark Enterprises to develop an expandable microgrid solution for the fast-growing industrial and business park based in Takoradi, Western Ghana.

The Westpark aims to eliminate many of the challenges faced by companies doing business in Sub-Sahara Africa, such as access to reliable power, water, broadband internet and transport.

 The new industrial park is poised to accelerate the transformation of Takoradi – Ghana’s third-largest city.To lay the foundations for reliable, competitive and efficient energy, WestPark has entered into a partnership with Siemens.

As part of the agreement, Siemens will develop a 250kW microgrid that controls the energy generation for the initial phase of buildings to be constructed at WestPark.

Siemens will design the microgrid so that the first phase of WestPark can be powered entirely by renewable energy and therefore provide a sustainable and cost-effective solution for tenants.

On-site photovoltaic panels will power the microgrid and a back-up battery storage solution will be sourced as well.

The grid can be expanded as more buildings are added with the aim of ensuring that the park remains powered by renewable energy.

According to Sabine Dall’Omo, CEO of Siemens Southern and Eastern Africa, “This project is perfectly in line with Siemens’ vision for future business in Ghana and other African countries. As a company, we are continuously looking for new responsible and efficient energy and infrastructure solutions, and our collaboration with WestPark is a good example of how we can support partners with similar goals.”

Siemens is specifically committed to economic growth across Africa, and in doing so in a forward-thinking manner by implementing environmentally sustainable solutions that will help its partners and customers succeed in today’s environmentally-conscious global market.

Siemens AG is a German conglomerate company headquartered in Berlin and Munich and the largest industrial manufacturing company in Europe with branch offices abroad. The principal divisions of the company are Industry, Energy, Healthcare, and Infrastructure & Cities, which represent the main activities of the company.