Business Rates and SEG: The Overlooked Solar Savings

Most commercial solar cases are built on one number: the price of the panels. That is the wrong place to stop. Two factors that sit outside the headline install cost can move the return by thousands of pounds a year, and both are routinely left out of the sums. The first is the England business rates exemption for rooftop solar, which runs until March 2035. The second is the Smart Export Guarantee (SEG), which pays you for the power you send back to the grid. Understanding how these interact with your chosen funding route often matters more than shaving a few percent off the capital price.

The business rates exemption most owners miss

In England, eligible plant and machinery used to generate renewable energy is exempt from business rates. For rooftop solar installed for self consumption, that exemption applies from 1 April 2022 to 31 March 2035. In plain terms, adding a solar array to your roof does not increase the rateable value of your property during that window, and you are not charged extra rates for the equipment.

That matters because, before this relief, installing generating plant could push up a property’s assessment and leave the owner paying more in rates every year for the privilege of producing their own electricity. Removing that penalty changes the arithmetic. The saving is not a one off; it is an annual cost that never appears on the bill for the life of the exemption.

The practical effect is simple. When you model the return on a system, you are comparing the cost of finance against the value of the electricity you no longer buy plus any export income, with no offsetting rise in rates. That clean picture is what makes the payback calculation work in your favour. You can test the effect for your own building using the finance calculator and see it reflected in the payback and ROI figures.

A note before we go further: this is general information, not tax advice. Business rates treatment, timing and eligibility depend on your property and how the system is used, so confirm the position with your accountant or a rating surveyor before you commit.

SEG: getting paid for what you export

The Smart Export Guarantee replaced the old Feed in Tariff. Under SEG, licensed electricity suppliers pay you for the surplus power your system exports to the grid. Installations up to 5 MW are eligible, which covers the overwhelming majority of commercial rooftop and ground mounted schemes.

Two points shape how much SEG is worth to you. First, you are paid per unit exported, so the rate and the volume both matter, and tariffs vary between suppliers. Second, self consumed electricity is almost always worth more than exported electricity, because avoiding a purchase at commercial retail prices saves more than the export tariff pays. The right design maximises the power you use on site during daylight, then earns SEG on the genuine surplus.

For a business with steady daytime demand, a warehouse, a manufacturing unit, a cold store, most of the generation is consumed on site and SEG is a useful top up. For a site that is quiet during the day, export income becomes a larger share of the return, and the SEG tariff you can secure starts to influence which finance route makes sense.

How these two factors change the finance decision

Rates exemption and SEG both improve the net return, which in turn affects how much finance a project can comfortably support and which route fits best. Here is how the common routes respond.

Finance route	Who owns the system	Do you keep SEG income	Benefits from rates exemption	Best when
Capital purchase	You	Yes	Yes	Cash available, want the full return
Hire purchase	You, after final payment	Yes	Yes	Want ownership but spread the cost
Asset finance	You, at term end	Yes	Yes	Preserve working capital, keep the asset
Business solar loan	You	Yes	Yes	Keep cash, borrow against the saving
Operating lease	The funder	Usually the funder	Depends on structure	Off balance sheet, no ownership goal
Power purchase agreement	The funder	The funder	Funder holds the asset	No upfront cost, pay per unit used
No upfront cost	The funder	The funder	Funder holds the asset	Zero capital, fixed price per unit

The pattern is clear. Where you own the system, whether outright or through hire purchase, asset finance or a loan, you keep both the SEG export income and the full benefit of the rates exemption. That ownership value is exactly what supports the repayments, and it is why owned routes tend to deliver the strongest lifetime return.

Where a funder owns the asset, as with a power purchase agreement or a no upfront structure, the export income and the rates position generally sit with them, and you pay a fixed or agreed rate for the electricity you use. That can still be a sound choice if preserving capital or avoiding ownership is the priority; you simply trade some upside for zero outlay and a predictable unit cost.

Don’t forget the tax and VAT position

The rates exemption and SEG sit alongside the capital allowances position, and it pays to get all of it right.

Solar PV is treated as special rate plant, so it does not qualify for 100% full expensing, which is main rate only, nor for the newer 40% first year allowance. It does qualify for the Annual Investment Allowance, which gives 100% first year relief on qualifying spend up to £1m a year. That cap covers most commercial installs outright. Where spend exceeds the AIA limit, companies can claim the 50% special rate first year allowance on the excess, with the balance then written down at 6% a year.

On VAT, commercial solar is charged at the standard 20% rate. The 0% domestic rate does not apply to commercial installations. If your business is VAT registered, that 20% is normally reclaimable, so it is a cash flow timing point rather than a permanent cost.

Again, this is general information and not tax advice. Allowances, VAT recovery and the interaction with your wider tax position depend on your circumstances, so confirm the detail with your accountant before you rely on it. You can see how these figures feed into a full cost picture on the cost page.

Bringing it together

The overlooked savings are not marginal. An annual rates saving you never pay, plus SEG income on genuine surplus, plus first year tax relief through the AIA, can shift a project from borderline to clearly worthwhile. The route you choose then decides who captures that value: you, if you own the system, or the funder, if you take a no capital option in exchange for zero outlay.

The only way to see the real numbers for your building is to compare costed quotes side by side, with the rates exemption, realistic SEG assumptions and your finance route all built in. That is what this service is for. We are a comparison and quote engine, not a lender or financial adviser, and we connect you with vetted MCS certified installers and funders so you can weigh the options on like for like terms.

Start by reviewing the finance options compared, then request costed quotes tailored to your site. A short brief about your building and daytime demand is enough for us to return figures that reflect the savings other quotes tend to leave out.