Many of our customers have installed an immersion optimiser to divert excess solar PV into their hot water tank.
If you have an electric vehicle (EV), it makes sense to divert excess electricity into the EV battery. In fact if your hot water is heated by gas, oil or biomass, it makes more sense to charge the car than it does to charge the hot water tank. An iBoost is generally displacing fuel costing ~ 5p per kWh, and so 1kWh of diverted electricity is worth ~ 5p. Charging the EV displaces grid electricity at the ‘full value’ ~ 16p per kWh.
zappi is an EV charging point with special eco charging modes to optimise self-consumption of on-site solar PV, wind etc. Specifically it has three charging modes:
With the Min Green Level set to 10%, charging will be paused if more than 1260W of power is being imported from the grid, and will resume as soon as 140W or more is being exported from solar.
By setting the Min Green Level to 100%, the car will be charged using only surplus renewable power, providing there is sufficient surplus power to do so.
Note: The EV charging standard does not support charging below 1.4kW.
To supplement the ECO and ECO+ modes, there are various optional boost functions, designed to ensure your car achieves minimum levels of charge whatever the weather. More on these below.
The zappi charger is available in either a 7kW single phase or 22kW 3-phase version. You can choose either of these with a tethered Type 2 6.5m cable or untethered, and in a white or black finish.
The single phase 7kW version is suitable for most domestic installations, while the 3-phase is ideal for commercial properties where this electricity supply is available.
It’s worth noting that the myenergi zappi charger complies with the BS7671 18th Edition regulations which came into force in January 2019. Currently it is the only available chargepoint that doesn’t require an earth rod for most installs, which gives rise to a significant installation cost saving relative to other chargepoints.
How much does zappi cost? Only £100 more than a standard charger...
The average cost of a second generation zappi installed is around £950 (including VAT and OZEV grant), depending on cabling requirements. This is about £100 more expensive than a standard charger. The zappi is OZEV approved and therefore eligible for the OZEV grant of £350, which is only available for installs of smart chargers like the zappi. You can claim the OZEV grant if you have proof of purchase of an electric vehicle on the eligible vehicle list (must cost less than £60,000) - see our guide to the full criteria.
eddi is similar to an iBoost or Immersun, in that it diverts excess solar generation to the hot water tank. If you install zappi and eddi, you can choose whether to prioritise zappi or eddi.
If you have a zappi or eddi, you can remotely control and monitor these devices with the internet-connected myenergi hub. This means you can track your usage of surplus energy going into car charging or heating.
zappi responds quicker than the immersion optimiser, and so the default will be that zappi will be switched on before the optimiser. If you don’t want this to happen, you can set a delay on the zappi to give the optimiser time to turn on.
If you have a DC coupled battery system, the battery will always take priority over the zappi. If you have an AC coupled system (e.g. Tesla Powerwall 2), the battery system is likely to have a similar response time to zappi. Therefore you need to set a delay on the zappi if you want to prioritise charging of your battery over your zappi. If you want to prioritise the zappi over the battery there is a workaround we can install using a CT clamp – this will tell the zappi when the battery is being charged, thus turning on the zappi, subject to sufficient power availability.
To supplement the ECO and ECO+ modes, there are various optional boost functions, designed to ensure your car achieves minimum levels of charge whatever the weather.
zappi’s a great product with all bases covered – just what you need if you drive an EV and you want to optimise the use of your solar. It is supplied at a very modest premium to the cost of a standard charger, and qualifies for the OZEV grant where relevant.
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