August 6, 2025 Solar Power

Sometimes, a business will generate more energy than it can use at that point in time. That presents the question of what to do with that surplus. You can sell that power, or if you have batteries, you can store it for use at a later date. 

When you’re making the decision as to whether to store or sell, it is wise to factor in the purpose for your solar installation and the business goals it is serving. Here is your guide to the facts, factors, and considerations that should inform your decision for your surplus electricity. 

The Smart Export Guarantee (SEG) is the scheme through which generators of renewable power can sell it back to an energy supplier. Suppliers are obliged to pay for the power, but the only requirement on the price is that it is higher than zero. 

Beyond that, the supplier decides the tariff, and the commercial reality is that you will not be paid what the energy is worth. Naturally, suppliers want to make a margin, and with almost no floor on what they have to pay, they might only offer you a negligible sum. 

Now, if you generate very high volumes of power, that small payment might still represent a worthwhile figure in terms of pounds and pence, but on a smaller scale, a solar surplus is likely worth more to the business as stored energy than as exported energy. 

At a given period in time, you could choose to store or export based on factors like the market, the tariff rate, and how much energy you already have stored. 

In deciding on sale or storage of a solar surplus, the best and first question to ask is ‘What is our primary purpose for solar power?’ That will help to focus your decision-making and should clarify the best approach. 

• If you have ESG targets related to decarbonisation, or want to demonstrate your sustainability to partners and government bodies, then storing your energy will probably be the most useful approach. Solar power is zero carbon energy, and if you have enough stored, then you may seldom if ever need to resort to using grid energy with CO₂e emissions. 

• Similarly, if you are aiming for total (or greater) energy independence, then a backup supply reduces the likelihood that you will need to resort to buying energy. 

• If you are aiming for the fastest ROI possible on your solar installation, shortening the payback period and getting free electricity as soon as you can, then it might be a good idea to take advantage of the SEG, so that your solar power is generating revenue as well as making savings. Make sure, though, that you generate enough electricity for that to have an impact, and make sure that it doesn’t make you resort to grid power too often, which could undermine the rate of your returns. 

• If you offer EV charging for your team, or you have an EV fleet, then storage makes a lot of sense. Frequent car charging can demand a lot of power, and if you aren’t generating much at a given time and don’t have a supply in storage, that charging will use grid power, which will be expensive and possibly polluting. 

Certain hours of operation make it clear choice to use storage. At the risk of stating the obvious, if your organisation is open or working at night time, your panels will not be generating power at that point. If you want inexpensive and zero-carbon power still, you will need to have stored a surplus from daylight hours. 

If your organisation or business is closed at the weekend, your solar panels will still be working even though you’re not using the power. You could sell that excess through the SEG, but that two days’ worth of solar power will be worth far more to you as backup power during short winter days and very cloudy weather. 

Still need some help deciding on whether to store or sell your surplus solar power? A renewable energy expert will be able to help you conclude which is best for you. 

Innasol takes a design-led approach to solar panel installation, which not only means finding solutions to maximise solar ROI for your business, but also helping to design a system specifically for the way that you will use solar. As part of our survey and consultation process, we discuss your goals for solar and propose a solar power system that work towards those outcomes, including battery storage if that makes sense for the project. 

For a no-obligation chat about solar and whether it is the right renewable energy system for your business, call 01621 892613 and one of our green specialists will be delighted to discuss it.