Zero Energy Homes: How to Take Control of Your Energy
Photo Renew Guernsey.
Due to the pandemic, we’ve all been spending a lot more time at home recently, and along with the many financial fallouts that have come with it, it’s also pushed up our energy bills quite considerably. This coupled with last years 4.8% price rise in electricity has perhaps made us sit up and take extra note of our energy use of late.
Covid has also seen us turn to spending money on home improvements as we all look for ways to enhance our properties, and as energy bills become increasingly front and centre in our minds, the case for installing renewables has never been more pertinent.
The “great pause” has also come at a time when the world is facing another huge challenge, climate change. And as we all start to try and figure out how to reduce our carbon footprint, one great place to begin and one which will make the biggest impact is in our homes. Buildings are a huge contributor to carbon emissions, in fact, 40% of emissions in the UK come from homes and due to the similarity in buildings, this will almost be identical in Guernsey.
Because our homes have a massive part to play in mitigating climate change, we can all do our bit, and at the same time significantly reduce our energy bills, all while providing a solid return on investment. As the price of electricity in Guernsey is not predicted to decrease and with the trend likely to rise again in the future, it’s now more important than ever to begin taking control of our energy.
Zero Energy Buildings
Occupants of homes can make massive savings on their energy bills if their properties are designed or retrofitted to what we envisage will be a future standard called Zero Energy Buildings.
Zero Energy Buildings are all about the energy a building can produce on-site using renewable energy technology and how much energy the building consumes, i.e. the number of units generated vs. units consumed. Buildings must be all-electric to start scoring, therefore if the home is heated by oil or gas, it doesn’t get a score, simply because carbon cannot be offset by renewable energy. Once you’re able to generate power the rating increases. Some homes may not be able to achieve complete Zero Energy status, but doing as much as one can can give the building a very good energy rating, improving the running costs overall and reducing its carbon footprint.
Ultimately, we think it’s important for Guernsey to establish such a rating scorecard so that building owners know their energy status, and make adjustments accordingly. In Guernsey there are no such policies or regulations regarding energy efficiency or renewable energy technologies at the moment, because of this uptake has been slow. But if a Zero Energy rating system was incorporated into building regulations, this will aid in making the island Carbon Zero and help in the fight against climate change. So how can we make our homes achieve Zero Energy status?
Solar PV
Building integrated Solar PV provide a highly aesthetic and sleek look to a building. This system is 8KW and adds to an existing solar thermal system and heat pump. All monitoring and heating control is internet-connected and works as a smart home concept, all interactive and automated. Photo Renew Guernsey.
They can be mounted on roofs, both pitched and flat, walls, verandas, carports, pergolas and on the ground. They can be directly integrated into the roof, pretty well anywhere, south, east or west, as long as not in direct shade all day. “Solar Photovoltaic” is the formal name for these type of solar panels and are commonly abbreviated to “Solar PV” or just “PV”.
Solar PV harness the light from the sun and convert it into electricity, this electric power then goes directly into your home appliances and if you generate more than you use this gets automatically directed out to the cables in the road and used by the surrounding area or the Island and you connect to the energy community. This energy is called ‘exported’ electricity, and you get rewarded for it by Guernsey Electricity with their ‘buy back’ tariff. The amount sent to the ‘grid’ in this way is noted on your statements and deducted from your bill. If you are not exporting, you are ‘offsetting’ the power you are using and so saving money on energy you would have otherwise had to pay for.
How much can I save on my bills with PV?
You can save 10%, 50% or 100% making your home “energy positive”. It’s all down to how you manage the consumption of your electricity and how you might change your use habits in relation to the solar production. For example, some people stick on the washing machine when it's sunny, or there are automatic systems that might boost the hot water when there is excess energy. Of course, the number of panels you have the more you save, so the tendency is to maximise the output to maximise savings.
An island of ‘self-generators’ all contributing to the grid will have a profound effect on our island. Generating our very own Guernsey green energy allows power to devolve to islanders by creating an energy community. Rather than relying on external agencies, generating our own power in our backyard gives us self-responsibility and self-satisfaction. Further, this contributes to an energy independent island that can generate its own power rather than relying on foreign energy companies, keeping money on shore, providing security of supply, boosting our economy and creating local jobs.
The UK government has decided under its Future Homes Standard that all new homes will have to be ‘zero carbon ready’ by 2025, with a focus on eliminating gas and oil heating. And it’s only a matter of time before Guernsey follows suit as the new States implement the recently voted Climate Change Policy and Action Plan. So as we begin to push away from fossil fuels, what is the most sustainable alternative for heating and hot water?
HEAT PUMPS
Mitsubishi Ecodan Air Source Heat Pumps provide hot water and central heating at a far lower cost compared to any other form of heating. Photo Mitsubishi Electric.
Air Source Heat Pumps are by far one of the most energy efficient forms of heating, using 3-4 times less energy compared to oil, gas and direct electric, offering the cheapest way to heat your home, using only a small amount of electricity to facilitate the transfer of energy from the air to the home. And that’s where your Solar PV comes into play, making Heat Pumps and Solar the perfect combo to maximise savings. Air Source Heat Pumps are renewable energy devices because they take heat from the outside air and transfer it into hot water and central heating to heat radiators or underfloor heating or a combination. Essentially it’s the same technology as a fridge but in reverse.
Ground Source Heat Pumps are also another great option if you want to reduce your long term running costs. They work the same way as Air Source, but take heat from pipes filled with water in the ground instead of from the air. Ground Source is even more efficient than Air Source due to the fact that heat is transferred through ground loops using water and water has a greater capacity to hold heat compared to air. However, as ground-works or boreholes are required to install the pipes, this can push up the up front cost of the installation, despite this they can provide a very solid return on investment.
Whatever Heat Pump solution you choose though, you’re definitely going to cut down on your bills and it's going to cut down your carbon emissions considerably if you currently use oil or gas. It’s no wonder Boris Johnson has promised to have 600,000 heat pumps installed every year in the UK by 2028.
The ‘Fifth Fuel’
The ‘fifth fuel’ a phrase coined by American physicist and environmental scientist Amory Lovins almost three decades ago means units of energy saved by efficiency and conservation. To get the best out of your Heat Pump and Solar PV, energy efficiency must be considered, as it leads to less energy having to be used improving productivity across the board.
For example, LED lighting uses less energy than incandescent light bulbs, and so this means there will be more of your solar energy available to use somewhere else. Heat loss can occur through the ceiling and walls, so it’s worth considering your insulation levels especially if your house was built some time ago, because the recommended amount of insulation installed at the time may not meet today’s standards and may be inadequate. Ensuring your home is well insulated means your heat pump doesn’t have to work so hard to heat it, and so again less electricity has to be used.
If energy efficiency is poorly thought out in the initial design process of a new building, this can prove costly later on down the line when you’re having to spend out on retrofitting your home in an effort to bring expensive running costs down. So best get it right first time.
Home automation is also worth considering, monitoring generation and consumption utilising IoT devices is a great way to keep on top of your energy, and there are a number of solutions on the market provided by energy specialists like ourselves! Energy monitoring systems are now starting to come with solar inverters too, and there’s now more products then ever helping you conserve your energy while you sleep.
Electric Vehicles
The Volkswagen all-electric ID.3. Photo Volkswagen.
Although we are focusing on buildings, we can’t ignore many of us are now charging our cars from home. So if you have an EV, or planning on buying one in the future, it’s even more prudent to install Solar and it’s especially important to make sure you spec out enough solar panels to power both your house and car.
It would also be worth considering a car charger that has the ability to read the power being generated by your solar panels, so you can top up your vehicle from the sun. The Mini Pro 2 by EO is a great product that comes with a Smart Home app, so you can set when your vehicle will charge according to the output of your solar array.
So there you have it, Zero Energy Buildings, self-reliant, autonomous, comfortable homes for the 21st Century. Taking control of your energy needs has never been easier, so why not join the self-generating energy community, and reduce your running costs, all while protecting the planet. Wins all round.
By Jack Fletcher