How to Power an Off-grid House
There are very few places that cannot be connected to the mains or national grid in the UK. Despite that, some renovators and self builders prefer going the off-grid energy route while others will have access to one form of energy but not another.
Whatever your situation, there are options for providing cost-effective, reliable energy to your home.
Even if you can connect to the grid, there is a lot to be said for energy independence. We are increasingly relying on imported energy and nuclear power. Neither of which are particularly sustainable.
Plus, with energy prices increasing all the time and price capping having little effect, there is even more benefit to going off-grid.
So, what are your options for powering an off-grid house?
Green energy options
You have five practical, affordable options to provide renewable energy to an off-grid house.
- Solar panels
- Wind turbine
- Ground source heat pump
- Hybrid systems
Let’s take a quick look at each.
Solar is a very viable method of powering an off-grid house. Panels are becoming cheaper and more efficient and solar panels can still generate energy even when there is little sun. There are also often incentives to help cover the cost and once installed, there is very little maintenance involved.
Solar is perhaps the best option for green energy as long as you have a south facing roof or spare land to place ground mounted panels.
As long as those requirements are met, solar has around 5 hours per day of sunlight to produce enough energy to power the house. That energy can be used as it’s generated or stored in batteries to provide power throughout the day and night.
Domestic wind turbines aren’t quite as popular as solar panels but they are an option. They are much more obvious than solar panels but if you live by the sea or somewhere with a steady breeze, wind can be a very viable way to generate renewable energy.
Where solar panels have improved in efficiency, so have wind turbines. They are now smaller and more efficient than ever before. You no longer need a huge turbine taking up your entire back garden.
A modest sized turbine could generate anything up to 10kW in the right position, providing energy throughout the day or night. Also, like solar panels, energy can be stored in batteries for use when there is no wind.
Ground source heat pump
A ground source heat pump, or geothermal can provide heating but not electricity. It works by drilling down deep into the earth where it’s warmer and using a simple pump and pipe system to warm water from the earth and pump it around your home to keep it warm.
Pumps are very efficient and pipes can be drilled into the ground or buried horizontally under your garden. Either way, the ground heats a mixture of water and antifreeze and pumps it around your home to keep it warm.
Ground source heat pumps are superb at maintaining a constant temperature whatever the weather for a very low running cost.
Domestic hydroelectric power is rare but is a feasible way of powering an off-grid house. It utilises power harnessed from flowing water in a smaller version of a hydroelectric dam.
Hydroelectric obviously requires a water source running through or next to the property sufficient to power a small turbine but if you have that, this is a viable off-grid energy source.
Water power is almost inexhaustible. As long as the river or stream flows, you can generate energy. That energy can be stored like any renewable in batteries.
In theory, a domestic hydroelectric system could generate anything up to 50kW but the locations and situations you can use it are very limited.
Hybrid off-grid systems
Hybrid off-grid systems use a combination of solar and wind or solar and geothermal. Wind and solar are the most common combination thanks to their relative low cost and ease of installation.
This combination means you should have a steady supply of energy regardless of the British weather, which is why these hybrid systems are so popular!
Depending on how much energy you would need to generate, a hybrid system wouldn’t have to be more expensive than a single source. You would use fewer panels and a smaller turbine in concert to deliver the required power so it wouldn’t have to cost much more at all.
Our Most Popular Off-grid Solar Kits for Homes
Calculating your power requirements
Before you go about building your off-grid energy system, you need to have a good idea of how much energy you need.
According to Ofgem, the average British home uses:
Low Use (kWh)
Medium Use (kWh)
High Use (kWh)
As every home is different and we all live different lifestyles, use these only as an average. We tend to use 3,800kWh as the average to provide a margin of error.
If you want to get more specific, we have an energy calculator that can estimate your average energy use. It’s an accurate calculator we recommend to our customers looking at solar panel systems or off-grid solutions.
If you would prefer to do it yourself, you need to calculate watt hours per day for each appliance. Then turn that into kilowatts kW and then multiply that by months or a year.
- Device wattage (watts) x hours used per day = Watt-hours (Wh) per day
- Device usage (Wh) / 1000 (Wh/kWh) = device usage in kWh
- Daily usage (kWh) x 30 = approximate monthly usage – kWh per month
- Daily usage (kWh) x 365 = approximate annual usage – kWh per year
There is a lot of working out to do but the maths is quite straightforward.
So, for example, a 150w TV used for 3 hours per day – 3 x 150w = 450w ÷ 1000 to get kWh = 0.45kWh x 30 for the month = 13.5 kWh. Or x 365 = 164.25 kWh for the year.
Repeat for every appliance you use.
Backup energy solutions
All of the sources we mentioned above offer reliable, sustainable ways of powering an off-grid house. However, what about those days when there is no sun or wind?
We recommend an efficient generator to provide energy and a log or biomass burner to provide heat for colder days.
Not every off-grid home will require a generator as a backup but if you know there will be days with very little wind and/or sun, they make an excellent insurance policy to help you run essential appliances.
Generators can be connected to off-grid systems to automatically take over when there is insufficient power being supplied to the batteries or they can be manually operated. We recommend automatic systems so your freezer won’t be without power for too long or when you’re not home.
Having a log or biomass burner around is an excellent backup for heating. They are nice to have around anyway but can fulfil a practical application with minimum cost and effort.
Whether you’re going off-grid because you have no choice or because you want to make that choice, you have more options than ever before to live the life you want without having to make compromises.
Solar panels, wind turbines, geothermal solutions, microhydro and hybrid systems can all provide consistent renewable energy at a relatively low cost. While there will be an initial investment, given how energy prices are going, you’ll get a return within just a few years!
If you’re planning an off-grid energy project, contact Sunstore. We can work with you to specify the perfect energy solution for your off-grid home. Call us on 01903 21 31 41 or complete the form for a fast, free quotation.
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