Solar PV, Batteries and Electric Vehicles are taking off in the UK in a big way. Buyers of these innovative technologies are driven by two things – savings on energy, and the significant carbon reductions these technologies offer.
However, the often overlooked key to unlocking these technologies’ maximum potential is electricity tariffs.
This article will briefly go over the options available to you if you have PV, battery, or an EV in the UK, to help you get the most out of your system.
If you’re on just PV and looking to save money, your best import tariff is the best value import tariff. We highly recommend using a energy provider switching service (such as Which’s Switch) to find out which deal is best for you, as there are factors such as contract length and whether you want a dual-fuel tariff that may affect your decision.
If you’re looking for maximum carbon reductions, we’d recommend going for the 100% renewable tariffs available from providers such as Octopus, or Ovo.
If you’re looking for the best SEG tariff for your solar, then Social Energy (5.6p/kWh) and Octopus (5.5p/kWh) are the best rates available as of November 2020.
For battery-only systems, saving the most money means charging the battery on cheap electricity, and then using that energy when the price is higher. This can be done on Economy-7 tariffs from most providers – however, there are two tariffs from Octopus that really make sense for this setup.
The most sensible option is the Octopus Go tariff. Despite being designed for EVs, the rates make a lot of sense for battery owners as well. With a 5p/kWh rate overnight (00:30-04:30), and 13.8p/kWh the rest of the day, your battery will save 8p per kilowatt-hour it stores charging overnight. This equates to about £1 a day in savings if you have the Tesla Powerwall.
If you want a bit more risk but higher reward, the Octopus Agile tariff is tied to half-hourly grid prices – so prices vary from close to zero overnight, through to 30p/kWh over the peak period between 4pm-7pm. Because your battery can provide energy over the expensive period, you’ll make stacks of savings. There’s a fantastic, free third-party tool available here to help you see how much you could save on the Octopus Agile tariff.
If you own just an electric vehicle, then by far the best tariff available on the market is the Octopus Go tariff. At just 13p/kWh day rate and 5p/kWh overnight, you’ll save on your energy during the day too. We estimate you’ll pay around a third less on your net energy costs than on a comparable Economy-7 tariff from a big Six provider.
For the majority of battery owners, we’d recommend the Octopus Go tariff for PV+Battery setups. The fantastic rate during the day is better than most flat rate tariffs, let alone all other variable rate tariffs (such as Economy 7 tariffs from Big Six providers).
However, if you own a Tesla Powerwall in addition to at least 4kW of PV, you could get a better deal. Octopus offer the ‘Tesla Energy Plan’, which has an 11p per kWh import and export (SEG) rate. This is the best flat rate tariff available by quite a margin, and double the next best energy export tariff which comes in 5.6p per kWh. As it is currently a trial, there is currently no standing charge (typically 25p/day)and no contract, so you can cancel any time if it doesn’t work out.
The best tariff in this case – if you don’t own a Tesla car or a Tesla Powerwall – is likely to be the Octopus Go tariff – offering 13.8p per kWh, and 5p between 00:30 and 04:30. This tariff lets you charge your car and battery overnight at just 5p per kWh, which results in great cost per mile – and with solar providing energy during the day, your overall daytime use is likely to be minimal.
If you own a Tesla vehicle and a Tesla Powerwall as well as 4kW of solar, you’re eligible for an upgraded offer of Octopus’s Tesla Energy Plan – 8p per kWh both import and export, all day every day. This beats all other tariffs by a mile. The only caveat that Tesla need to have control of the battery for their energy trading to work. As it is currently a trial, there is currently no standing charge (typically 25p/day) and no contract, 0so you can cancel any time if it doesn’t work out.