Where did solar power come from? How do we know it works? When is it going to be applied on a large scale?
If you’re considering solar panels for your home or business, the questions above might be running through your mind. It’s fully understandable that you’d be questioning this technology, especially as the world has run on coal for so long.
It turns out in a recent survey of UK residents carried out by Project Solar, that 34% of people think that new builds are going to have to include solar as their energy source in the next 50 years. Whilst this isn’t being enforced yet, the current trend of new governmental legislations do seem to suggest it is a possibility (especially if the UK wants to only be producing clean energy by 2035).
This timeline that we’ve made should help you understand a bit more about how solar energy was first converted into electricity, and how you’ll be seeing a lot more of it from now on.
In the last two centuries, solar power has come leaps and bounds. It’s incredible to see how quickly solar technology has advanced. Whilst it’s quickly becoming one of the most common alternative energy sources, not many people know how the technology got to where it is today.
In this year the first solar cell was created by Alexandre Edmond Becquerel. Aged just 19, he was experimenting in his father’s lab when he made a startling discovery. Upon connecting platinum electrodes to silver chloride in an acidic solution, the young scientist observed that a current and voltage were generated whenever the materials were exposed to light. After more experiments and testing, this technology wasn’t generating enough electricity to be used as a viable power source, so for now, solar cells were only useful for measuring light.
An American inventor named Charles Fritts invented the first functional solar panels. He did this by coating a thin layer of an element called selenium with a very thin layer of gold. Although these first panels were only effective at converting 1% of the solar energy hitting them into electricity, they still showed that it is possible to take a substantial amount of energy from sunlight and convert it into electricity.
So how do solar panels actually work? Light goes in, and electricity comes out, until 1905 panels had just been made with experimentation. This was the year that Einstein changed everything.
At this point in his life, Einstein wasn’t the famed worldwide physicist we all think of him as today, but just a patent clerk in Switzerland. He released a paper building on the work of Max Planck, who explained that particles can absorb or emit radiation in discrete “quanta”. Einstein’s paper went on to extend Planck’s theory to light.
In simple terms, Einstein stated that light (which was only thought of as a wave up until this point) was actually made up of a beam of particles known as photons. These photons each had their own different levels of energy which depended on how fast they were vibrating. He then explained that if you aimed this beam of photons at a metal, something interesting could happen.
The flow of these electrons is what we know today as electricity. In Einstein’s 1905 paper, he described that if the photons from a beam of light had enough energy, they could knock electrons from the atoms on the surface of a metal. This release, or flow of electrons, results in a current and voltage being generated. This theory is known as the “photoelectric effect”, and was the first full explanation we had for how solar panels worked.
Einstein would later go on to win a Nobel Prize for his explanation of the photoelectric effect, and as we still rely on it to make solar panels more than a hundred years later, it’s easy to see why!
Robert Millikan designed and carried out an experiment in order to disprove Einstein’s photoelectric effect theory. This experiment was actually a failure as it ended up proving the existence of the photoelectric effect (you can find out more on Millikan’s experiment here).
This was the year that the first silicon-based solar panels were developed at Bell Labs. The work that led up to this discovery started 14 years earlier when Russell Ohl was researching silicon as a semiconductor.
Ohl found that one of his samples had a crack in it, and when exposed to light it allowed current to flow through it. He had unknowingly just discovered the p-n junction, which is a key part of modern solar panels (you can learn more about p-n junctions here).
Over the next few years, the scientists at Bell Labs worked on making solar cells and eventually a solar panel using silicon. Daryl Chapin, Calvin Fuller, and Gerald Pearson were the scientists responsible for the creation of the first silicon-based solar panel. They unveiled the invention on April 25th 1954 and used solar power to run a small Ferris wheel toy and a radio transmitter.
On July 27th 1994, electricity generated from solar panels on private property was donated back to the UK grid for the first time. This landmark event occurred in Southwell, Nottinghamshire. This was part of Brenda and Robert Vale’s “Autonomous House”, where they designed a property to be completely self-sufficient in energy and water. They outlined this in theory in 1975, and just under 20 years later is when they saw their dream realised.
In August of 2006, Curry’s announced that they would start to stock solar pan modules at £1,000 each from Sharp, with an installation service also provided. If you adjust for inflation this is equal to £1,522.57 in 2023. This milestone showed the start of major retailers and businesses taking domestic solar power seriously in the UK.
By the end of the year, the country had reached 12 MW of solar capacity. This is a fairly significant figure when you take into account that the first solar-powered home was only introduced just over 10 years prior.
In April this year the Feed-in-Tariff (FiT) subsidy was introduced. This tariff allowed homeowners to receive payments for electricity generated by eligible sustainable means – like solar panels.
The money to fund the FiT came from energy suppliers and was regulated by Ofgem E-Serve. Although this scheme is no longer taking new applications in 2019, homeowners who applied before this deadline are still receiving payments.
The UK government announced that a target of 4 million homes would be powered by solar energy by 2020, which would require the national solar capacity to reach 22 GW of capacity.
In 2020, the solar capacity of the UK was 13.477 GW. This is substantially less than the ambitious target of 22 GW. This may be partially attributed to COVID-19 impacting plans for large-scale solar farms.
The total UK solar capacity surpassed 10,000 MW in 2006, achieving a major milestone for solar as an alternative energy source.
From April to September in the UK solar panels produced more energy than coal. This started on April 9th, when for the first time ever, solar energy surpassed coal in the UK. The significance of this landmark cannot be understated, as it represents the sustained investment into UK renewable energy from the government and solar companies.
On the 1st of January, a replacement was launched for the FiT scheme which stopped taking new applicants in 2019. The Smart Export Guarantee (SEG) was introduced by the UK government to encourage homes and businesses to generate solar power and other renewable forms of energy.
The main difference between the FiT and SEG is that the SEG will only pay for energy exported back to the grid, whereas the FiT also paid for the energy homeowners or businesses generated as a whole.
In 2022 document L was released and under it, a whole set of regulations for the construction of new homes. On 15th June 2023, the grace period for this legislation ends, meaning that all new homes submitted for planning after this date must produce 31% fewer CO₂ emissions than homes built under the previous regulations.
As a follow-on from document L coming into effect, the UK Future Homes and Buildings Standard will start being enforced in 2025. This new legislation aims to ensure new homes will produce 75-80% fewer carbon emissions than those built under previous regulations.
For buildings such as shops, offices, and other businesses, the legislation will cut their emissions by 27%. This legislation is coming into effect to help the country reach its targets in reducing carbon emissions.
In 2035, the UK government have set a target for all electricity generated to come from zero-carbon emitting sources. This huge commitment to sustainable energy sources means we will see a rise in solar capacity, wind farms, and other non-carbon-emitting energy sources.
A major factor in how the government aims to do this is through the Contracts for Difference (CfD) scheme. The CfDs are effectively long-term contracts for energy site developers that are designed to offer the developer a guarantee over price certainty for the duration of the contract. In simpler terms, it minimises unexpected costs for developers of renewable energy farms.
The reality behind this decarbonisation target is that electricity produced from coal is damaging to the environment. The target is a vital step for the country to reach its ultimate climate goals.
Net zero greenhouse gas emissions by 2050. That’s the main UK government target for sustainability in this country. This is hoped to be achieved through significant decarbonisation in many sectors, not limited to but including generating energy.
It is now clearer than before that the UK is on a path towards sustainable energy generation for the long term. With the numerous government targets and legislations aimed at cutting carbon emissions and greenhouse gases, it’s not really a question as to ‘if’ you’ll switch to a more renewable lifestyle, but more of a ‘when’.
So what’s next for the UK? Will communities start coming together to own solar farms? 12% of UK residents surveyed by Project Solar seem to think this is a strong possibility in the coming 50 years. Whilst there are often questions about different generations looking out for themselves, in the same survey almost 70% of over 55-year-olds believe that all homes will be solar-powered in the coming years. If that isn’t an endorsement from the generation that relied almost solely on coal, we don’t know what is.
If you would like to find out more about switching to a more renewable lifestyle with solar panels, visit our homepage.