Solar panels, batteries and grid congestion: save more by using your own power as net metering ends

For years the case for solar panels on a business roof was simple. Under net metering the meter ran backwards whenever the panels produced more than you used, so every kilowatt-hour counted at the full retail price. In a growing number of countries and states that no longer holds. Export payments worth far less than the power you buy are replacing net metering, and where there is grid congestion the grid operator may have no room for the power you feed in or the load you want to add.

Both problems have the same answer: use as much of your own solar power as you can when it is generated, and keep your peak low. A fictitious cold store below shows what that is worth.

What is grid congestion?

Grid congestion means the electricity network in an area cannot carry more demand or supply at its busiest moments. New or heavier connections then wait in a queue or come with conditions. The International Energy Agency (IEA) describes a lack of grid capacity as a bottleneck in many regions and reports record connection queues worldwide (source: IEA, February 2026). It also notes that grids are built for peak demand and often have substantial unused capacity outside peak periods (source: IEA, February 2026). That is the opening for a business: the grid lacks room at certain hours, not all day.

For a business, congestion means a waiting list for a heavier connection, an export limit on new panels, or an offer of a non-firm connection: faster access, but your use or output may be limited at certain times (source: IEA, February 2026). Rationing rules differ by country; some operators give priority to projects that relieve congestion or serve public needs. A place in the queue changes the order, not the capacity, so apply as soon as a plan is serious.

Net metering is ending: how exported solar power is valued

• Check your country: the export model and its end date, feed-in charges, the export limit at your address, which taxes and network charges you avoid on own use, and whether you can get prices that vary by hour. Export rules are under review in many markets, so check the regulator's page before every investment.

Why self-consumption now beats export

The gap between those two lines is the whole argument. Under net metering it was zero; without it, every kilowatt-hour you move from export to own use earns the difference. If you reclaim VAT, leave VAT out of the saving; if your business cannot reclaim it, as in parts of healthcare and education, count it in.

How to get more out of your current connection

Worked example: a cold store loses net metering

Tidewell Cold Storage keeps chilled and frozen food for regional wholesalers and uses 180,000 kWh a year. Its rooftop panels cost €96,000 and produce 110,000 kWh a year. Under net metering every kilowatt-hour counted at the purchase price of €0.24. Under the new rules its supplier pays €0.05 per exported kWh and charges €0.01 in feed-in costs, so an exported kWh is worth €0.04. Without changes, 66,000 kWh is used on site and 44,000 kWh is exported.

Fictitious Firmfocus example. A: 110,000 x €0.24 = €26,400. B: 66,000 x €0.24 = €15,840 plus 44,000 x €0.04 = €1,760. C: 80,000 x €0.24 = €19,200 plus 30,000 x €0.04 = €1,200. D: the battery takes in 20,000 kWh and delivers 18,000 kWh after losses; 98,000 x €0.24 = €23,520 plus 10,000 x €0.04 = €400. The logic works in any currency.

Doing nothing costs Tidewell €8,800 a year and stretches the payback of its panels from 3.6 years (€96,000 / €26,400) to 5.5 years (€96,000 / €17,600). Shifting is the cheapest fix: pre-cooling the freezer rooms a few degrees at midday, moving defrost cycles and charging the electric forklifts in daylight. The controls cost €6,000 and earn €2,800 a year, a payback of 2.1 years.

The battery is a closer call. On stored solar alone it earns €3,520 a year, almost 13 years to pay back €45,000. But it also keeps the evening peak, when compressors and dock doors work hardest, below the connection limit, which cuts the capacity charge by €2,500. With both jobs counted it earns €6,020 a year and pays back in 7.5 years. Judge a battery on every job it does.

Small connection or large connection

Solar panels on a business roof: checklist

• Roof: have the load checked, and renew an ageing roof covering before the panels go on.
• Grid: ask the grid operator how much you may export at your address.
• Size: match the system to daytime use, not to roof area.
• Inverter: choose one certified for your local grid code and register the installation.
• Incentives: many allowances and grants must be applied for before you commit; see funding for sustainability.

Get a grip on your power use in four steps

1. 01

   Map your use per hour

   Request interval data and find when your peak falls.

2. 02

   Check the grid at your address

   Ask about export limits, queues and flexible contracts.

3. 03

   Move flexible loads

   Shift charging, cooling and production into solar hours and out of the evening peak.

4. 04

   Calculate against own use

   Value each investment on self-consumption and today's export terms, not on old net metering rules.

Pitfalls

• Old sums: a quote that still values every kilowatt-hour at the retail price.
• Forgetting that export needs capacity: in a congested area an oversized system gets capped.
• Missing feed-in charges: they can push the value of exported power close to zero.
• A battery for one job: storing solar alone seldom pays.
• Expecting a new contract to move the queue: it does not.

Solar and storage work best next to the other energy measures in this series: read about energy efficiency obligations, charging an electric fleet under sustainable mobility, and how own generation lowers your carbon footprint. Grants are covered in grants and public funding, and the full series starts at Sustainable business.