5 solar energy systems - Grand Designs Magazine
solar panels on a detached house

5 solar energy systems and their benefits

The renewable and cost-saving benefits of installing solar energy options in your home

By Gemma Parkes |

One of the most powerful sources of energy is the sun. And with the price of solar energy systems coming down, as energy bills go up, embracing this low-carbon, renewable energy source makes more sense now than ever.

Plus, with the government’s Future Homes Standard – which will require new-build homes to have low-carbon heating and be more energy efficient – due to be introduced by 2025, it makes sense for self-builders to get ahead of the curve.

The most effective way to utilise the sun’s energy is to install solar panels into your home, but with so many different options available it can be difficult to know which solar energy system is right for your property, and how cost-effective it really is.

house greenskies ST lifestyle flat plate system Worcester Bosch

Photo: Greenskies Solar Lifestyle flat plate system by Worcester Bosch

1. Solar PV panels to generate electricity

Solar photovoltaic (PV) panels convert sunlight into electricity to run appliances and lighting. They are made up of cells and their power is measured in kilowatts peak (kWp).

An inverter converts the power collected from a direct current to the alternating current that’s needed to run appliances. A solar battery can store excess electricity generated during the day, so it can be used when the amount produced is low. Costs vary, but solar panels will now set you back about 25% less than they did in 2014. The Energy Saving Trust estimates that a 3.5kWp domestic solar PV panel system will cost around £4,800 and can knock £120-£310 a year off your electricity bill.

Unfortunately, the government’s Feed-in Tariff (FIT) – which earned you money from every kWh of electricity produced – closed in 2019. But the Smart Export Guarantee (SEG) came into effect on 1 January 2020, offering small-scale low-carbon electricity generators (up to 5MW capacity) payment for any surplus energy exported back to the National Grid. Suppliers with over 150,000 customers are obliged to offer a tariff, while those with fewer can partake on a voluntary basis, so look for a supplier that offers SEG.

house with roof top six panel solar panel system ikea

Photo: Rooftop six-panel PV 3kWp system by IKEA Home Solar Business

One of the most powerful sources of energy is the sun. And with the price of solar energy systems coming down, as energy bills go up, embracing this low-carbon, renewable energy source makes more sense now than ever.

Plus, with the government’s Future Homes Standard – which will require new-build homes to have low-carbon heating and be more energy efficient – due to be introduced by 2025, it makes sense for self-builders to get ahead of the curve.

The most effective way to utilise the sun’s energy is to install solar panels into your home, but with so many different options available it can be difficult to know which solar energy system is right for your property, and how cost-effective it really is.

house greenskies ST lifestyle flat plate system Worcester Bosch

Photo: Greenskies Solar Lifestyle flat plate system by Worcester Bosch

1. Solar PV panels to generate electricity

Solar photovoltaic (PV) panels convert sunlight into electricity to run appliances and lighting. They are made up of cells and their power is measured in kilowatts peak (kWp).

An inverter converts the power collected from a direct current to the alternating current that’s needed to run appliances. A solar battery can store excess electricity generated during the day, so it can be used when the amount produced is low. Costs vary, but solar panels will now set you back about 25% less than they did in 2014. The Energy Saving Trust estimates that a 3.5kWp domestic solar PV panel system will cost around £4,800 and can knock £120-£310 a year off your electricity bill.

Unfortunately, the government’s Feed-in Tariff (FIT) – which earned you money from every kWh of electricity produced – closed in 2019. But the Smart Export Guarantee (SEG) came into effect on 1 January 2020, offering small-scale low-carbon electricity generators (up to 5MW capacity) payment for any surplus energy exported back to the National Grid. Suppliers with over 150,000 customers are obliged to offer a tariff, while those with fewer can partake on a voluntary basis, so look for a supplier that offers SEG.

house with roof top six panel solar panel system ikea

Photo: Rooftop six-panel PV 3kWp system by IKEA Home Solar Business

Image: This Solar PV 5.34kWp system integrates seamlessly with the curved wooden roof panels. Price on application, EvoEnergy

2. Solar Thermal Systems for hot water

Solar Thermal Systems use the sun’s warmth to heat water, which is stored in a twin coil hot water cylinder. There are two types to choose from: flat plate, which is cheaper, or evacuated tube, which is more efficient. The Energy Saving Trust recommends installing about one square metre panel per person and a well-specified system delivers around 60% of a family’s annual hot water requirement, reducing energy bills and lowering your carbon footprint. You’ll need a boiler or heat pump for heating and to provide hot water when the system isn’t producing enough during winter months.

Solar water heating qualifies for the Renewable Heat Incentive (RHI), a government scheme that pays householders for generating heat using renewable energy. Properties need to meet minimum efficiency standards and the current rate is 21.49p per kWh (find the latest RHI tariff table here). Note that the scheme closes to new applications at midnight on 31 March 2022.

‘While solar thermal isn’t as popular in the UK as it was, and it often loses the battle for roof space with solar PV, the technology is well subsidised by the RHI. We’d strongly advise anyone installing a heating system to make it solar thermal compatible, if not for now, then for the future,’ says Darren McMahon, marketing director at Viessmann.

3. Integrated solar panels for listed buildings or conservation areas

New technology is bringing integrated panels and tiles to self-builders and renovators who want to incorporate solar PV or ST systems into the fabric of their roof.

‘Integrated solar panels are fixed above roofing membrane and battens, replacing the tiles for a sleek, low profile,’ says Stuart Elmes of Viridian Solar. Solar slate roof tiles are unobtrusive, improve energy efficiency and are an option for listed buildings and conservation areas.

The experts at Viridian Solar also explain the benefits of opting for above-roof solar PV over roof-integrated solar PV. ‘Above-roof systems will operate at a lower temperature due to better ventilation. Since soar PV power output falls as panel temperature rises the argument goes that roof integrated solar will have a lower energy yield.

Viridian Solar and researchers from the University of Cambridge have examined this effect. The published research found that the reduction in energy yield was very small, of order only 3%.’

flat plate ST solar panel system on roof top of house

Photo: Flat-plat ST system with ThermoProtect by Viessmann

4. Evacuated tube solar thermal systems for efficiency

A solar array doesn’t need to be mounted on the roof but it does need to be as south-facing as possible, and set on an incline close to 30 degrees, otherwise performance drops off. Evacuated tube solar thermal systems are slightly more tolerant to being other than south-facing, but to work effectively all panels need to be free from any shadows cast by surrounding trees and buildings, plus PV panels need more roof space.

The UK’s premier energy saving advice portal, The Green Age, describes how ‘solar thermal harness the sun’s energy by turning the solar radiation into heat which is usually used for water’.

They go on to advise that a ‘typical evacuated tube solar collector system will cost about £3,000-£5,000 to get installed on your property, and will typically produce about 1,000-2,500 kWh of useful heat – or about 50% of your hot water requirements.’

house with greenonetec ST solar system panels

Photo: Greenonetec ST system with panels around 4sqm by Norfolk Solar

5. Photovoltalic Thermal Systems for renewable low-cost energy

A Photovoltaic Thermal System (PVT) yields hot water and electricity from the same panel. Systems don’t benefit from the RHI incentive scheme, so PVT is for people who want to reduce running costs by producing as much renewable low-cost energy as they can.

New innovations allow hybrid panels to use wasted heat from electricity generation and convert it to energy for hot water.

A great example of this system in action is the Solar House in Leicestershire. Constructed in 2013, it was Britain’s first solar-powered zero-carbon home. Developed by sustainability specialist Caplin Homes, the five-bedroom house was designed to harness enough solar power to provide heating and hot water, and double the amount of electricity required to run them.

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