Homely & HEMS: Optimising the Electrified Home
Homely was always looking into the future to provide a more sustainable way to use our energy. As we were building Homely we placed a lot of emphasis on these future ambitions – Full house optimisation and Demand Side Response being examples of our forward looking considerations.
Homely is the smartest way to control a heat pump but we strongly believe that it is soon to be the smartest way to optimise the electrified home. Our in-house Math modelers have been working hard to create and test the algorithms for the solution to be able to distribute loads around the system. We’ve already seen impressive results in a live environment.
Now, we are ready to start recruiting Alpha testers. Interested? Read on.
Our current test system
Our test system is already being controlled by Homely.
What does it do?
Homely is connected using a Modbus connection (just a two wire connection) to a Midea heat pump and a battery.
Homely is controlling:
- Scheduling hot water to come on during the times when the sun is shining and is not used up by other loads in the property or using my cheap overnight tariff (depending on the solar forecast for the day ahead)
Homely is communicating the leaving water temperature to the heat pump to make sure that:
- When the sun is not forecasted to shine, the heat pump is used more during the night, heating the test house 1C above the set-point using the cheaper 5p/kWh overnight tariff. If there isn’t enough heat in the house throughout the day after this pre-heat, Homely will modulate the heat pump to the lowest possible flow temperature to maintain a comfortable temperature indoors at the highest heat pump efficiency levels possible.
- When the sun is going to shine, Homely would attempt to modulate the heat pump power consumption to the production of the PV.
- Let’s say your heat pump can consume a maximum of 4kW at full power but the available solar is only 2kW. Homely will reduce the operation of the heat pump to get closer to the power production of the PV or even matching it at 2kW.
- Homely is communicating the charging and discharging rates to the battery, making sure the battery charges just enough overnight to fulfill the load for the day, whilst being supplemented by the PV. The ultimate goal is to not export PV into the grid. In order to do that we don’t want the battery to be full (even with 5p/kWh electricity) when the sun comes out.
- To do this Homely uses solar forecasts for the day ahead to know how much the battery should charge overnight
- At the test house, the PV and battery were installed at separate times so don’t have a hybrid inverter. Currently, the battery monitors the excess solar.
As the EV charger is managed by the electricity supplier, we want to make sure we don’t inadvertently discharge the battery into the EV. To ensure this, Homely is connected using a CT clamp to the EV charger to make sure that when the battery is discharging into the house it only fulfills other loads of the house, and the EV requirements are coming from the grid.
What benefit is it already delivering? Consider these user cases…
Homely will consider the next day’s solar production forecasts and will ensure that the battery is not fully charged to make sure we can fully utilise solar.
Additionally, Homely is also be able to predict what the rest of the house power consumption will be doing, to make sure that the battery is sufficiently charged during the cheap times. So, if we are still using power before the sun comes out the battery has enough charge for this.
Even though the price of electricity is cheaper overnight, it’s still money thrown away compared to what I could be absorbing from the sun.
This one is easy, Homely already does it.
Homely has got you covered. We can install a current clamp on the EV charger and make sure that the battery never gets discharged into the EV.
Yes! Homely will be able to react to Agile tariffs everyday downloading these from Octopus
We’re excited about this one. Homely is like having your own personal energy trader sitting in your home controlling the battery, charging when it’s cheaper and discharging into the grid when it’s expensive.
Great for the individual, but there are wider societal benefit as well.
- By charging your battery during the cheaper times you make sure that the cheap (often more renewable) electricity is soaked up from the grid when not being used by others.
- Discharging into the grid when it’s expensive. There is already a shortage of electricity in the system so you’re helping out. Rather than expensive, high pollutant power plants being turned on, it’s the renewable power that was stored in your battery that is powering the grid. Of course, there is also the side benefit that you’re getting paid to do so.
Not a problem. Just enter the tariff details into Homely
Not a problem. We can monitor PV ourselves through current clamps
Homely was designed with Heat Pump controls first. That’s not to say that Homely can’t pivot. If you’re interested in this kind of solution then let us know!
We are currently working on our integrations. We already have support for
- Alpha Ess
The next ones on the list will be:
We plan to increase this list rapidly. Want to see your preferred battery prioritised? Just let us know.