Solar Panel Batteries Battery for Solar PV

Written-by

Richard Burdett

Reviewed-by

Richard Burdett

Updated on

Sep 04, 2024

Solar Panel Batteries Battery for Solar PV

Solar Storage

We’ve had solar panels for a good while now and many of us have them installed on our roofs. One of the major hurdles to energy independence, however, has so far eluded us – namely how to store that valuable electricity on site for use locally when the sun isn’t shining. This development has the potential to make each home energy independent and to greatly reduce our reliance on large utility companies and the National Grid. It’s one of the big innovations of the last few years and it is beginning to gather pace.

In short, solar power technology for solar panels could revolutionise the way we use energy. The good news is that in recent years the solar storage industry has started to move forward and with products from companies like Tesla and Samsung the future is starting to look much brighter. Many suppliers and installers are now incorporating combined solar and storage when they visit a customer. These are undoubtedly relatively early days but this new technology could allow the solar industry to thrive without the need for subsidies paid by us through our utility bills.

How Storage Works at the Moment

Solar panels fit on your roof and attract the energy from the sun. They use solar cells to convert this energy to electricity and currently provide power for homes and businesses across the UK. At the moment, this electricity is produced mainly when the sun is shining onto the panels and is then sent to the National Grid.

Homes and businesses with solar panels basically sell their electricity to the utility companies and receive a set amount through the Smart Export Guarantee (SEG) in return – basically the Grid acts as the storage mechanism ensuring we have power 24/7.

Why We Need Storage

When solar first started to become a possibility in the early 80s and 90s, the idea of power storage and how to achieve it locally was at the forefront of developers’ minds. Eventually, the solution to pour the power back into the grid took precedence and actually led many people to decide to have panels installed on their roofs. Not only that, many businesses and organisations began to see it as a way of boosting their green credentials and reducing their energy bills.

All this, however, depended on a certain amount of subsidy with the utility companies paying for the electricity produced. The problem is this is benefit for having them installed is about to be dramatically reduced by the Government. There has always been a desire to create a system that is actually independent of the grid and storage development is now starting to come full circle again with efficient batteries that can be placed in homes or businesses, making them energy sufficient without relying on the National Grid.

In other words, the creation of a workable storage solution should allow people to use the electricity they produce 24/7, bypassing the need to pay utility companies. That’s all in theory. In practice, there are some hurdles to still overcome.

The Problem With Storing Your Own Electricity

For a long time the problems with solar power storage units were their efficiency, how long they were going to last before they needed replacing and the ongoing cost compared to accessing the National Grid. In the initial stages, the prospect of a good return on investment was limited but there seems to have been a real sea change in the last two years which means that prices are set to come down and the quality of product is beginning to improve.

The initial costing for the much vaunted Tesla battery was around £10,000 but has come down dramatically to £2,000 in a pretty short space of time. Many companies are starting to position themselves now as suppliers and installers of solar storage units that could literally change the way we look at power supplies and our own, individual energy independence, both at home and in the commercial sector.

How Solar Storage Works

Systems with the ability to store their own electricity for solar have three vital components:

• Solar panels that collect the energy from the sun and convert it to DC electricity.
• A battery or series of batteries that store the electricity produced.
• An inverter that converts DC current to AC so that it can be used around the home.
   

The main point about in-house batteries is that they need to store enough electricity to get a home or business through that period when the solar panels are practically dormant. The average home uses in the region of 5,000 kW/h per year or 13 to 14 kW/h per day and much of this is either early in the morning or in the evening (assuming the house is empty during the day).

How much you use will define the number of batteries you have installed and the overall cost if you want to make sure you are covered in times of greatest need.

Tesla Batteries

One of the prime movers in the solar power storage market has been Tesla, perhaps better known for their work on hybrid and electric cars to date. They have used the technology they have developed in the car manufacturing market to produce a lithium ion battery which they call Powerwall. They currently produce a 7 kW daily and 10 kW weekly battery that is easy to install and provides power for when your solar panels are not producing electricity. These are guaranteed for 10 years and can provide the energy needed for a normal working home.

Additional batteries can be added for those with higher electricity needs. The Powerwall also contains the inverter to convert DC current to AC. Weighing about the same as an average person, the Tesla Powerwall is certainly a large piece of kit and costs between £2,000 and £2,500 (not including installation and install prices vary wildly). Tesla began shipping their 7 kW version of the battery to the UK in September 2015.

Much depends on whether the market starts to take up this kind of technology in large numbers and that is going to depend on a number of factors, including overall cost, efficiency and longevity.

Samsung SDI Batteries and Other Providers

Tesla are not the only solar power storage units that are starting to make their way onto the market. Samsung SDIhave produced 5.5 kW and 8 kW versions which were unveiled at an event in Munich in 2015. These have a warranty for five years and performance is guaranteed for 10.

Their Residential ESS system is said to be ideal for homes but they also produce much larger batteries up to utility level and will no doubt be one of the big players on the market over the next few years. Players such as LG Chem and even Mercedes Benz have also entered the market and their presence is starting to drive the prices down for solar storage, giving consumers a greater degree of choice.

Can You Go Off Grid?

This is the big challenge for solar storage – whether we can cut off our supply from the National Grid and actually be electricity independent from the utility companies. The trouble is that, whilst the market is beginning to expand and the technology is developing more rapidly, there is always the worry of what happens when your capacity over-reaches or the battery develops a fault. If you have disconnected yourself from the mains supply then what do you do without any electricity at all?

Then there is the cost of maintaining and replacing batteries and the long term issues of basically being your own, independent energy manufacturer. The truth is it may be a little too soon for some people to opt for the installation of solar storage batteries – it will probably take more time for consumers to adopt them on a large scale.

For businesses with larger systems that need someone onsite to maintain the power it can add even more costs – that of employing people to do the job and the problem if power is suddenly taken away and the consequent loss of sales and revenue.

Storage That’s Not Just for Solar

The truth is that a battery storage system can be used for any renewable system, including hydroelectric and wind turbines. The unique position of solar is that it only produces sufficient electricity when the sun is shining but storage could also be used for other energy systems to help with times when there is a strain on capacity; for instance, when a factory has a large order to complete.

The Future of Solar Energy Storage

Intelligent storage may well be the future of greater energy independence, at least in the shorter term. Many developers are now beginning to produce digital technologies that monitor energy usage and combine that with power production to make sure that electricity is available as and when needed.

For instance, in an average home where everyone is working, more power is used in the morning and in the evening than during the day. Businesses will have other peak demands that will benefit from a more controlled energy storage system. Batteries with a much longer lifespan and better capacity will also help make the break from a total reliance on the National Grid and lead us to more independent electricity production.

In the immediate future it may well be the case that we will need a hybrid mechanism that stores electricity but also has access to the National Grid. That will then reduce the amount of electricity that requires a payment to the utility companies but will also require the development of further technology. In the longer term, we may have a situation where localised energy storage will indeed mean that many of us can become independent of the National Grid.

The question will be how the installation is funded and whether universal access can be created which means we all benefit from clean energy that is homemade. You can find local installers and suppliers of solar panels and storage systems on our database.

Battery Storage for Solar Panels

Since solar panels became financially viable one major stumbling block to the power they generate day to day has been how to use the energy when the sun isn’t shining. Up until recently it has been impossible to store your excess solar energy safely and cost-effectively. However, there are now many solar panel battery storage solutions breaking on to the market. They vary in size and cost from a load of bread to around the size of a dishwasher and all have the ultimate aim of reducing your reliance on the National Grid.

Why We Need Storage

When solar power first started to emerge on the market, the concept of power storage and how to achieve it became a heavily discussed topic, and spend quite some time at the forefront of the minds of developers. However, the quick and easy solution of channelling excess power back to the grid took centre stage, leading a great number of people to have panels installed on their roofs.

In addition to this, a number of businesses and organisations also started to see solar panels as a way of boosting their image when it came to green energy, as well as a means of reducing their energy bills overall. However, a lot of this remained dependent on a subsidy that had the utility companies paying for the electricity that was produced. The issue with this is, and the reason we need battery storage, that the benefit that comes with having them installed will soon be greatly reduced by the government.

In some ways, this is a good thing as it will lead to the further research and development of systems that are independent of the grid. We are already seeing some of the benefits with efficient batteries that can be placed in homes or businesses being released. What this means is that we have a workable storage solution that should allow people to use the electricity they produce at any time they wish. All without needing to pay utility companies.

How it Works

Each of the solar battery banks is designed for a specific charge or discharge level. Some of them are manufactured wet cells, and others are manufactured sealed or gel cells – each of which has their own requirements. Always make sure you read the manual and ask the manufacturers for advice if you get stuck. When you decide to use a battery storage system, you should always make sure that it is the appropriate size and quality for the amount of solar power that it will be required to store. They should also be a deep cycle battery, unlike a car battery which is classed as a shallow cycle.

Using a battery that is too small can be incredibly dangerous. Modern batteries are now made of Lithium so can charge and discharge many more times and can store considerably more energy for their size. This technology requires no maintenance for the lifetime of the battery system, much like your mobile phone battery but many, many times the size. Batteries do make great ways to store the energy produced by solar power, and they can offer you the chance to be free from the grid.

It is important to remember that when you are using batteries, they some tend to require a lot more maintenance, and currently they do not last 20 years like your solar panels. They require storage in a safe, enclosed, location that is well ventilated and non-metallic. We do not recommend anyone tries to make their own battery at home especially on grid-tied systems.

DC batteries will required to be installed by an MCS accredited installer as this will most probably require an inverter change or special retrofit. For AC fed batteries, the process is slightly easier as the battery system operates separately from the PV system and has its own AC to DC inverter built in. These systems are slightly less efficient though but are often cheaper to buy initially.

It is also entirely possible to make your own batteries with materials that you can either obtain online or from your local hardware store. You may even have some of the items at home already. The list of required materials is actually very simple and not particularly long, and you can find a range of how-to guides online. It can be a great option because it is usually a lot cheaper than buying battery storage for your solar panels, as it usually costs at least £2,000 - £4,000.

However, you should also be asking yourself if it is wise for you to be making a battery large enough to store your excess solar energy. If you have the right experience and expertise, then there should be no issues. However, for those with no knowledge or training, it could have dangerous results. A faulty battery is a potentially deadly one, so as said previously, we strongly advise against this.

The Problems with Battery Storage

The main problem with battery storage for solar energy had always been rooted in their efficiency and how long they would last before they needed to be replaced, alongside the cost compared to remaining hooked up to the National Grid. Initially, the notion of a good return on your investment was incredibly limited, but over the past couple of years, there seems to have been quite a lot of things changing.

The main thing to note here is the dramatic decrease in price and increase in quality – a combination that you do not usually see. For example, the Tesla battery was priced at £10,000, and now it can be £2,000 (£4000 with installation). However, while the price has decreased dramatically, there are still issues with the concept of solar batteries. Most of this stems from the question “can you really leave the grid?”

A question that many have asked when faced with the prospect of a solar battery. After all, if you don’t produce enough power in the day and run out at night, you will be completely without power until the next morning if you are cut off from the grid. This is especially true when we take into consideration that you can expect around 20% of the power to be lost through natural means over the course of the day.

The Benefits of Battery Storage

If you decide to remain connected to the grid and your solar battery is essentially full, the excess will still be sent back to the grid, and you will still be eligible for payments for it. As the price of electricity rises, storing your excess means that you can become more cost effective, saving money and trying to dodge electricity bills from suppliers.

You can expect storage systems like this to become more efficient as energy prices rise. Battery storage is the first step to self-sufficiency.

Want to Know More?

Have you found yourself interested in solar panels? If you want to know more then make sure you head to our marketplace where you can find our full range of products, each with the relevant information. Or simply give us a ring using the number at the top of this page and have a chat.