A guide to solar energy: What are its advantages and disadvantages?

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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.

What is solar energy?

Put simply, solar energy is energy that’s derived from the power and heat – the radiation – from the sun. Importantly, this power exists whether or not we harness it for electricity in our homes. It’s the light and the warmth that creates and preserves life on our happy little planet. That’s what makes it a natural resource, as opposed to something manufactured. It’s there, whether we use it or not. In fact, it would be here even if we weren’t. 

Yes, the light and heat of the sun, which is solar power, can be used to generate electricity. And it’s this capability which makes it such an attractive prospect as a renewable energy source. 

But solar energy doesn’t exist because of the likes of solar panels. No matter how solar energy works in a practical sense for us, that energy is always there. What matters for the future of solar energy is how we use tools like solar panels to make the most of that eco-friendly solar power. 

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. 

Is solar energy renewable?

One of the key problems with some energy sources – such as fossil fuels like coal and oil – is that there’s a finite amount of them. If we were to use them indefinitely, we would eventually run out. That’s not to mention the environmental damage they would cause! These energy sources take hundreds of thousands of years to form and so are currently being used at a rate which is too fast for them to be replaced.

Renewable energy aims to solve this problem. It refers to an energy source that can naturally be replaced, so we never run out. Solar energy is not just renewable, it’s perhaps the ultimate renewable energy source – and one which doesn’t have a damaging impact on the environment. It gives us about 5 billion years or so of practically infinite energy without any signs of slowing down.

When debating ‘is solar power renewable or not’, some people argue that the sun’s lifespan is finite, as it will one day run out of hydrogen. But considering the billions of years that await us before that point, this is more a philosophical argument rather than a pragmatic one. For all practical purposes, solar power is renewable. The sun is an immense, clean and renewable source of energy that’s waiting for us to harvest all its potential.

How can solar power be used in the home?

The power from your solar 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! 

Is solar energy reliable?

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. 

But is solar energy reliable for keeping our homes switched on in gloomy Britain? Well, the good thing about solar panels 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 is solar energy stored?

There might be times when the sun is shining, but you don’t need to use the energy being generated. Or you might need power at night, when the sun isn’t shining. So, it’s good to be able to store all that energy for 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. 

There are a few options for storing solar energy at home. These include thermal stores, electricity batteries, heat batteries and saltwater batteries. You can find out more about your different solar energy storage options in our battery energy storage guide.

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 – Once your panels are installed, you can expect to reduce your energy bills by up to £310 a year. Remember though, you'll still need some electricity from the grid during the colder/darker months, and you'll still need to pay a daily standing charge to your supplier. The Energy Saving Trust can give you much more information about 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 tonne 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 – Since April 2020 the Smart Export Guarantee (SEG) has been available to those who produce their own energy.It offers payment for electricity generated and exported back to the grid.
• 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 energy¹.
• Cheaper to install year-on-year – Solar power is becoming increasingly mainstream in the residential market. In fact, the price of solar power fell by over 80% between 2010 and 2021,and we can reasonably expect prices to drop further.
• Easy to install – Getting the panels fitted isn’t a huge drama. But you will need to have scaffolding for up to a week, even if the panels only take a day or 2 to install.
• Low maintenance – Once installed, the panels quietly go on doing their thing for around 25-30 years – with some newer models even lasting up to 50 years². Most modern panels are also self-cleaning, so there’s no need to risk life and limb to go and give them a wipe down. 

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 solar storage for it too. 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. 

Plus, 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:

• Tidal or hydro energy 
• Wind energy
• Biomass

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? 

To find out more about solar energy and 19 other inspiring renewable energy facts, read our blog on 20 fascinating renewable energy facts. 

The future of solar energy

Although the future of solar energy has its unknowns, we have a pretty good idea of how things will likely look in the coming decades. 

The basics of how solar energy works will largely remain the same. But there are several important factors that will impact the use of solar energy. We’ll start with a simple yet vital part of the uptake of any new technology, and that’s cost. 

Greater affordability

Since the turn of the millennium, some costs have halved because certain materials have become cheaper, and engineering has become more cost-efficient. 

These factors – along with the ability to manufacture in bulk, as the technology becomes more popular – means that costs will hopefully continue to go down. 

Not only has solar energy become cheaper, but it has grown far more popular in recent years, as the world turns away from fossil fuels. It has become more acceptable, economical and ethical for companies and individuals to adopt solar power. 

Growing global demand

Political pressure has also accelerated the uptake of solar power. Environmental challenges the world faces have gone from being the focus of academics to something that almost everyone is aware of. The climate crisis is impacting all of our lives, and will continue to do so.

To combat this, nations from across the world have made renewable energy a priority. Ambitious emissions targets have been made to help limit global temperature increases. To meet these targets, technologies like solar power will have to be embraced on a massive scale. 

Innovations in technology

In terms of changes to the actual technology itself, there are various avenues to explore. As the race to find the most efficient and cost-effective system continues, it’s likely there’ll be several methods developed further. 

At Oxford University, for instance, researchers are testing using perovskites (a mineral created using calcium, titanium and oxygen) on panels. Their work shows how much energy a solar panel produces is something that can change. 

Other important fields of research are around storage, so that solar energy can be used more consistently and reliably across a variety of climates. 

There’s also some exciting potential developments in using floating solar panels, on lakes and oceans. This may be a technology that’s still in its infancy, but it’s an exciting glimpse into the possible future of solar energy.

Sources and references:

^{1https://www.solarpowerportal.co.uk/news/residential_solar_boosts_house_prices_by_average_of_30000}

^{2 https://www.renewableenergyhub.co.uk/main/solar-panels/how-long-do-solar-panels-last/}