Is it worth producing your own renewable energy?

It can be a very attractive thought to have a roof full of solar panels or a wind turbine to power your home, providing all the electricity you need from a renewable source right outside your door, but in reality, it’s not as simple as that, and most of the time people do not have the funds or space to build such things. So how do you decide if producing your own renewable energy is the right way, or even worth doing to begin with?

At the cheaper and easier end of the scale, you have the option of solar panels, or if you’re lucky enough to have a natural running water source on your property, then a water turbine would be even better. For most people who live in built-up areas, the only option would be solar panels, because a giant wind turbine is guaranteed to receive enough complaints from the locals to get it taken down.

As for producing your own renewable energy, you have to ask yourself what’s right for you.

The first on the list is by far the most popular and efficient for the average home, but one thing most people don’t know about solar panels is that the majority of houses that use them still draw energy off the grid as normal. A house covered in solar panels will usually draw electricity off the grid like every other house, with the energy their panels create going directly back into the grid. The house with then receive either a discount on their electricity bill or a payment if they created more electricity than they used.

Some homes have solar panels that directly power something within their home, but these are usually things like water heaters instead of regular appliances. There is the option to have your own battery and have a completely independent system, but this will be very expensive, dangerous, and leave you in the dark if there’s no sun for a few days.

How much will it cost and produce?

In the UK, the average home will use an average of 2700 to 3500 kWh per year for smaller to medium-sized homes, with the larger properties using between 3500 and 4000 kWh per year. If you had a lower requirement of around 2500 kWh annually, you would need between 12 and 15 panels that can produce 300 watts, taking up a roof space of between 20m² and 25m². The panels would also need to provide a combined wattage of between 3.5kw and 4kw since they never operate at the maximum capacity they are advertised at. A setup like this with installation would cost you £5,000 to £6,000, but if used sparingly and you were in a location with good sunlight, it could completely wipe out your electricity bill.

The problem is that the average annual cost of electricity for a UK home is only around £1200, and if you’re cutting back in your usage and can average £800 a year, it would take at least 7 or 8 years just to get your money back.

So are solar panels worth it?

Unless you can get a full solar panel setup on your home for considerably less than the average price, then unfortunately it isn’t worth it from a financial perspective. Having said that, there are many solar setups out there that people have put together for much less than the average cost. After searching for a while at the time of writing this, I managed to find a 3000w 24volt system for just over £900, which would only take 2 years to get your money back from, but as always with cheap equipment, you get what you pay for.

Wind energy

There are only two options with this one, and the names refer to the positions of the axis. The standard wind turbine is known as a horizontal axis wind turbine and can most often be seen in huge lines on the tops of hills or out to sea. These can produce huge amounts of electricity when there’s enough wind of course, but they are also far too big to put in a built-up area. The ones that are small enough to get away with, such as the kind of thing you could mount on the average shed, will barely produce enough electricity to power more than a small outdoor light.

the other option is the vertical wind turbine which can produce more electricity without needing to be as high up. It doesn’t matter what the direction of the wind is because they don’t need to reposition like their horizontal counterparts do, but can still be a bit of an eye-sore and will get enough complaints to stop them being built in most areas.

How much will it cost and produce?

If you live on a farm or in a remote area then you are much more likely to be allowed to build your wind turbine. A 5kw turbine will produce around 9,000 kWh on an average year, but will also cost about £25,000 to buy and install. This will pay for itself after about 20 years, but the average lifespan of a wind turbine is normally between 20 and 25 years.

Some suppliers offer smaller vertical wind turbines you can put in your garden without the need for planning permission since the base isn’t a permanent fixture. They are suspiciously cheap and claim to produce several kilowatts for the low cost of a few hundred pounds, and if this were true, they would pay for themselves and put you in profit after less than a year. If you are allowed to have a turbine or do not need permission, then the setup cost is everything, after this, they will pay for themselves and start providing a profit faster than solar panels will.

So are wind turbines worth it?

It depends entirely on the set-up costs because they can be several times what it would cost to have a full roof of solar panels. It is almost always cheaper to buy the separate parts and make the mast and structure yourself, especially if you are doing so on a small scale like on a shed. A small 1Kw turbine mounted on the roof of a home could save over £100 a year on the electricity bill, but a line of them would be needed to provide enough power to live off, and doing this won’t be allowed in most areas. Homes are also not designed to have them installed and special brackets and roof work will need to be paid for, so for an average home set-up, they won’t be worth it.

The other thing to be considered is if you are in a location that gets a constant and decent amount of wind. There is a big difference between a constant breeze and the kind of wind needed to produce a worthwhile amount of power. Elevated locations and anywhere wind can concentrate like in a valley are good options, but not so much for the average townhouse garden.

Water energy

This is only an option if you can build on a stream or river going through your land, but is also the best option by far. Unlike wind and solar energy, water doesn’t depend on the weather or time of day, and can produce a consistent amount of power. It is the best and safest option for directly powering a home or for an off-the-grid setup. Water wheels are the most commonly thought of type of water energy, but the most advanced and productive is known as a vortex turbine. These use the added force of gravity and the swirling of the vortex to produce more power with less water.

How much will a vortex turbine cost and produce?

The least amount of flow a water system can have in order to be worth using a turbine on is 0.25 m³/second, which will also need a drop of up to 3 meters for maximum efficiency. Vortex turbines work by utilizing gravity and the vortex effect of the water, which means there has to be a distance the water can fall to create this effect. Only streams or rivers flowing downhill or having drops big enough to build on are suitable but can produce a huge amount with a higher efficiency than wind or solar.

a 15KW system with a flow rate of 1m³/second with a drop of 2 meters will consistently produce around 13kw, night and day. This is enough to power ten homes but will still take years for the setup cost to be recovered. A system like this will cost between £15,000 and £35,000 to buy and install, and take about 15 years to pay for. Many foreign companies offer vortex turbines and the equipment that goes with them for up to ten times less than the average price, but how well this works comes down to whether the savings are worth the risk.

So is water energy worth it?

Yes if you build your own set-up. The individual parts are not expensive and can be bought separately, with the structure itself to hold it all having to be no more complicated than basic brick walls and concrete. A vortex turbine could be very expensive, but going a bit lower down the technology scale could be the answer using the classic waterwheel.

If you have no drop in your water system, then using the current to power a waterwheel is a much cheaper and easy-to-build solution. After buying the necessary inverter and other equipment, the wheel itself can be built out of nothing more than plastic, wood, or metal. Because water wheels can be expanded out from someone’s land, there isn’t any planning permission required, but there may be laws about blocking a part of the river.