Solar energy guide: what are its advantages and disadvantages?
By Celia Topping Tuesday 22 December 2020
Everybody loves the sunshine! All that lovely vitamin D makes us feel happier, healthier and less stressed. But, regardless of our serotonin levels, life on Earth would be impossible without the sun’s light and warmth. And as if that wasn’t enough, we can also rely on the sun for electricity too – in the form of solar power.
As we move away from fossil fuels towards a renewable energy future, sustainable power from solar, wind, tidal and biomass sources are all alternative options. In the UK, Spring 2020 was the sunniest on record, with the highest amount of solar power ever produced. It’s no surprise that solar panel energy is fast becoming one of the leading renewable energy sources in the world today.
How does solar energy work?
This is a little bit technical, so bear with us. Solar power relies on a process called the photovoltaic effect. This is the ability to turn the sun’s radiation into electricity. It was discovered by a 19-year-old bright spark (sorry, pun intended) called Edmund Becquerel in 1839. Although the panels came a bit later.
Solar panels are made up of many photovoltaic cells. These cells contain silicon. When sunlight hits the silicon, it causes the electrons in them to start moving around. This movement creates electricity in the form of a direct current (DC) which is then converted into an alternating current (AC). This AC electricity can be used to power our homes and businesses.
The good thing about solar panels (especially in the UK!) is they don’t need bright, direct sunlight to power them – they work on cloudy days too. But essentially, more sun means more power. For example, a solar panel installed on a west or east facing roof rather than a south facing one will probably generate around 25% less energy.
How can solar power be used in the home?
The power from your panels gets converted directly into electricity, so you can use it for anything you would ordinarily use Grid electricity for. That includes everything from switching on a light to watching TV, plus heating water, and keeping your home warm. Once installed, you won’t notice any difference between solar power and Grid power.
If you’re interested in finding out more about solar panels and how people use them to power their homes, check out our guide and see if solar-powered energy might be the right option for your home.
And if you're interested in finding out more about the pros and cons of other renewable energy sources, this is the place to go!
How efficient is solar power?
One thing we can always rely on is the sun. So in that respect, solar power is both sustainable and renewable. But how much of that limitless power can be converted directly into electricity?
The first ever silicon PV solar cell, created in 1955, could convert sunlight at 4% efficiency. Not very impressive, is it? But, as you’d expect, this number has grown over the years, with efficiency now averaging at 15% to 20%. The more efficient your panels, the more you pay. But, as efficiency increases, prices will drop.
How is solar energy stored?
There may be times when the sun is shining, but you don’t need to use the energy being generated. Or you may need power at night, when the sun isn’t shining. So it’s good to be able to store all that solar energy, so it can be used when you need it. Without storage, you’ll only be able to use the solar power you generate in the hours of daylight. Then at night, the source of your electricity supply will switch seamlessly from solar to Grid.
Solar power can be stored in various ways in your home, including:
Thermal stores – solar generated energy is stored in highly-insulated hot water tanks. Meaning you don’t need to heat your water from other sources.
Electricity batteries – solar energy can be stored in these batteries to power all your household electricity once the sun has set. Lithium-ion batteries are commonly used, but they’re not a long term solution, due to their non-renewable lithium contents. For that reason alone, they’re not the most environmentally-friendly option.
Heat batteries – these store energy as heat to warm your home and water. They’re smaller and lighter than thermal stores, and are said to last longer than electricity batteries. But they’re not so common in the residential market yet. Find out how you could get one installed in your home as part of our Zero Carbon Heating Trial.
Saltwater batteries – a fairly new kid on the block, these batteries use the natural electrolytes found in saltwater to store energy.
If you live in Lincolnshire, get a battery installed for free with our #futureofenergy home battery storage trial.
Futuristic moment of the week! Crazy as it sounds, the batteries used to power electric vehicles (EV) could also be used as storage for domestic solar power. So not only would you be able to charge up your EV from your solar panels, but you could also put the power back into your home when you need it. A two-way energy flow system – the mind boggles!
Read more about this innovative process in our guide about electric car batteries.
What are the advantages of solar energy?
There are many benefits of powering your home with solar power:
Cutting your bills – sun power is free power – so once your panels are installed, there are no more charges, and you can reduce your energy bills by up to £220 a year. The Energy Saving Trust can give you more information on how much you can save, with their handy calculator.
Reducing your carbon footprint – it’s not all about the money. Solar power is clean, green energy, meaning it generates no carbon emissions (except in the manufacture of the panels themselves). Using solar power means you’re helping the UK, and the world, on our journey to zero carbon and meeting those all important climate change goals. A typical home using solar panels could save around 1.3 to 1.6 tonnes of carbon per year.
Reducing air and noise pollution – solar panel energy generation is silent, and the silicon used within the panels is non-toxic. As well as reducing carbon emissions and helping slow down climate change, you’re also reducing air pollution, a major global problem.
Earning money from your solar technology – until March 2019, solar powered homes could benefit from the Feed-in tariff (FIT). This offered payment for electricity generated, as well as a payment for the excess electricity that could be exported to the Grid. Registration for the FIT has now ended. But those already registered will receive payment until the end of their contract. Since April 2020, the Smart Export Guarantee (SEG) has been available instead, offering a similar deal.
Adding value to your home – far from being put off by the solar panels, prospective buyers are attracted by a more efficient home that generates its own energy.
Cheaper to install year-on-year – solar power is becoming increasingly mainstream in the residential market. So we can expect prices to drop even further than the 60% they’ve already come down in the last 10 years.
Easy to install – getting the panels fitted is not a big production. Remarkably, you can be up and running within a day or two.
Low maintenance – once installed, the panels quietly go on doing their thing for around 25-30 years. All they need is a very occasional wipe down to keep them dirt-free.
What are the disadvantages of solar energy?
Nothing is ever perfect. Although there are plenty of financial and environmental advantages to going solar, you need to consider the flip-side, too:
Initial cost – prices are dropping, but installing solar panels isn’t a cheap option yet.
Weather/daytime dependency – solar systems work on cloudy days, but they reach maximum efficiency when it's sunny. And of course, solar power doesn't work at night.
Aesthetics – they’re not pretty, and you wouldn’t be allowed to install them in conservation areas. But, there are new integrated designs being developed, which blend in with the roof in a more natural way.
Suitability – not all homes can have solar panels installed. If you have a flat or north-facing roof, it’s well worth checking their suitability. A south-facing roof with a 30 to 40-degree angle is ideal. If there are trees or tall buildings around your home, this could also cause issues. Detailed surveys should be carried out in advance, both inside and outside your home, to ensure your home is the right fit for a solar system.
Additional cost – solar technology is great. But are you always around, to use the energy it generates on a sunny day? And what about the money you pay for Grid electricity at night? To take full advantage of your solar panel power, you need to install storage for it too. And as we’ve seen above, this can be expensive. If power is not successfully stored, there will still be a reliance on the grid for power during cloudier spells and at night. Taking this into consideration, a combination of solar/grid is valid and still worth doing.
Is solar energy more expensive than regular energy?
Sunshine is free. But unfortunately, solar power is not. The manufacture, transport and installation of the solar panels is where the cost comes in. But as solar panel energy becomes mainstream, and more people get panels installed, those costs will come down. And, hopefully, in the not-too-distant future, solar power energy will be able to compete pricewise with fossil fuel energy. The tide is already turning, and the huge shift away from fossil fuel is well underway. This is good news for your wallet, and also for Planet Earth.
Can solar energy power the world?
It’s possible, but not necessarily desirable. Yes, we want to move away from fossil fuels and power the world on renewable, sustainable energy. But it would be good to use other renewable sources too – such as:
The International Energy Agency (IEA) recently claimed that the best solar power technology can offer the “cheapest…electricity in history.” A new and exciting solar-powered future awaits. Is right now the moment for you to be part of it?
Want to join the renewable energy revolution and fight climate change with OVO? Find out more about our energy plans and switch today!
To find out more about solar energy and 19 other inspiring renewable energy facts, read our blog on 20 fascinating renewable energy facts.