How to integrate a heat pump, solar panels and battery storage
Considering integrating a heat pump, solar panels and battery storage within your home?
In this article, we explain everything you need to know, from what to consider during installation, to how to maximise your cost and carbon savings from your technologies.
What to consider when installing a heat pump, solar panels and battery storage
Should I install solar panels or a heat pump first?
At Good Energy, we often get asked which technology a customer should install first: a heat pump, solar panels or a battery? In terms of how the technologies integrate with each other – it doesn’t matter which is installed first – it’s down to your own personal preferences. For example, many people choose to get a heat pump first due to their existing heating system being unreliable or too expensive.
However, if you have the choice, we suggest installing solar panels (and battery storage) first. These technologies can provide vast amounts of data about your home’s energy generation and demand, which is useful for optimising heat pump installation and usage.
Just make sure that you are clear with your solar panel installer about your desire to upgrade to a heat pump in the future, and ensure you get a hybrid inverter so generation and battery can work in tandem to meet your home’s electricity demands.
How many solar panels do I need to meet the demands of a heat pump?
Heat pumps use around 80% of their annual energy demand between 01 October and 31 March – when it’s coldest and the solar generation is often low. On very cold days heat pumps can use as much as 30 – 60 kWh a day depending on your house’s size and outside temperature, shown in the examples below.
On the flip side, solar panels generate approximately 80% of their annual power between 01 March and 30 September when the sun is higher and skies are clearer (dependent on factors like panel orientation and pitch).
Because of this mismatch in when power is used and generated, it’s unlikely that even the largest domestic solar array can fully cover the demand from your heat pump. To offset as much demand as possible, we recommend installing as many solar panels as you can fit on your rooftop, or as many as your budget allows, alongside a large domestic battery such as the Tesla Powerwall 3, which has 13.5kWh storage.
We suggest seeing how well one battery works for your home before adding more – Good Energy can always return at a later date to install an additional battery or a Tesla Powerwall expansion unit if your energy demand is particularly high.
“On warm summer days, my heat pump uses only 2kWh of power to heat my hot water, while my solar panels generate up to 30kWh.” Max
Do I need to join a smart tariff to maximise my savings?
The final part of the puzzle is adding a high-paying export tariff and a dual-rate smart tariff to truly maximise your savings from your technologies.
Export tariff: An export tariff will pay you for all of the solar electricity you don’t use in the summer – providing a large credit on your account to pay for the energy your heat pump uses in the winter.
Good Energy’s standard export tariff pays 15p / kWh; and our exclusive higher rate tariff pays 40p / kWh for 12 months. This tariff is available only to households that choose Good Energy to install their solar panels and battery.
Smart tariff: A dual-rate smart tariff enables you to charge up your battery at a low rate and then use that power during peak times. Good Energy currently has two smart tariffs available – a heat pump tariff (providing 7 hours of off-peak electricity spread over two sessions) and an Electric Vehicle tariff (providing 5 hours of off peak electricity in the night).
It’s important to note that a full 13.5kWh battery won’t provide all of your heat pump’s energy demand on a cold day – but it will go a long way towards reducing your energy costs.
Optimising your heat pump, solar panels and battery
What’s the best app to help me to manage and schedule my technologies?
At the moment you will need more than one app to schedule your heating, hot water and battery. However, it is likely this will change in the future as more and more homes electrify their heating. Good Energy’s solar team install SolarEdge products and Tesla products – both of which come with well designed, intuitive apps that provide a huge amount of data and control over your home’s energy usage. And while you won’t be able to segment your heat pump’s usage from your other electricity demand, you will see an overall picture of how your home uses energy.
The Tesla Powerwall app has two settings – Self-powered mode, which helps you to maximise using your solar-generated energy, and time-based control mode which maximises your cost-savings.
With this setting, you simply input your smart tariff rates and timings and your export tariff rates; and trust it to work in the background to save you money. This setting is self-learning – it analyses your energy use over days, weeks and seasons, looks at weather forecasts to predict upcoming generation or potential power cuts, and fills up your battery in the most-cost effective way each day.
The SolarEdge app also provides homeowners a great deal of control over their home energy, with several modes to choose between. While it isn’t self-learning, you can input your smart tariff and export tariff details in the same way, which will instruct your SolarEdge battery to fill during your off-peak window(s) to provide your home with low-cost power.
Your heat pump will also come with an app to help you manage your home’s temperature and schedule. At Good Energy, we install Tado thermometers alongside Midea heat pumps.
What’s the most-cost effective way to schedule my heat pump, solar panels and battery?
Depending on which home technologies you have, here are the Good Energy team’s suggestions to help you to maximise your cost-savings from your heat pump, solar panels and battery.
Just a heat pump: If you have a heat pump, and don’t yet have solar panels or a battery, the most cost-effective way to use it is to join a heat pump tariff. Our heat pump tariff is designed around average heat pump usage, and comes with two off-peak windows to reflect this: 5am-9am and 1pm-4pm. You can adjust your hot water heating and disinfection cycle to take place during these off-peak windows, and load shift some of your other electricity usage like the washing machine or tumble dryer too.
Heat pump and solar panels: If you have a heat pump and solar panels, we again suggest joining the heat pump tariff, and shifting your hot water heating and disinfection cycle to take place during your off-peak windows.
Your solar panels will support your heat pump running costs, and any electricity you don’t use you can get paid for through an export tariff – with a credit added directly to your account. If you also have a hot water diverter (like the SolarEdge Hot Water Controller or the MyEnergi Eddi), this will heat your tank during sunny days in the afternoon, helping your water stay hot for longer.
Heat pump, solar panels and battery: If your home set-up includes a battery, then you have a choice over two smart tariffs: our EV tariff provides 5 hours of continuous off-peak power between 12am and 5am, and our heat pump tariff has two slightly shorter off-peak windows, making up 7 hours of off-peak time in total.
You might opt for the EV tariff if you have an electric vehicle to charge and you need to head out early – otherwise our suggestion would be to choose the heat pump tariff.
You would then schedule your battery to charge from the grid during your off-peak window(s), or submit your tariff details and let your battery’s intelligent mode take over. You would schedule your hot water heating and disinfection cycle to take place during your off-peak window(s), and join an export tariff to get paid for your excess power year round.
Hear our experts talk heat pumps, solar and battery in this video
Good Energy’s expert teams install solar panels, battery storage, EV charge points, hot water diverters and heat pumps. On top of this we provide export tariffs and 100% renewable power, with two smart tariffs to help high-usage customers to lower their energy costs. If you want to make your whole home greener, Good Energy can help.
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