The process of converting solar energy into electricity in a solar power plant is done in three steps. Solar photovoltaic cells generate electricity, which is then converted to be suitable for use in the electric devices using an inverter. The electricity can be either consumed onsite, stored in batteries, or exported. In the UK context, the one of interest is an on-site installation that generates electricity for the business.
Solar Farms and Commercial Systems
Big solar power plants, which are known as solar farms, are the type of power plant that developers construct on large open land spaces to provide power for the grid sustainably. Transformers increase the voltage of the output from these sources so that they can be connected to the grid. Solar PV commercial plants are a different case and have another purpose as far as the size of their installation is concerned.
How Photovoltaic Panels Generate Electricity
The solar cells in the solar panels comprise semiconductors like silicon. As the solar energy falls on the solar cells, the electrons become energised, and the electric field present inside the solar cells drives the electrons towards one direction, resulting in the generation of DC electricity. Solar panels can be connected in series to form strings of higher voltages.
Solar photovoltaic panels operate on daylight rather than sunshine, and therefore electricity production is continued even during cloudy days, but at lower rates because of reduced sunlight; and stops when night falls. Shadows affect the rate of electricity production and therefore site surveying for obstructions such as trees, rooftop installations and nearby structures.
The Inverter's Role in a Solar Power Plant
Buildings and the grid run on alternating current (AC). The inverter is responsible for converting DC electricity to AC electricity and matching its voltage and frequency to the existing electricity at the site. In commercial solar arrays, the entire string is fed to one inverter, whereas each panel is handled by the microinverter. At the smallest scale, Solarfy's plug-in solar kits pair their panels with a Hoymiles microinverter.
How Solar Electricity Powers the Building
Once converted, the electricity feeds into the building's distribution board. No manual switching is involved. Lighting, refrigeration, computers and machinery draw on solar generation first, and the grid automatically covers any shortfall. Every unit used this way is one the business does not have to buy.
Surplus Electricity, the Grid and Battery Storage
Where the power generated by the solar panels is greater than what is needed in the building, for instance at times when the office is closed on the weekends yet there is sunshine, then the excess power is transmitted to the power grid using the meter. This is done through the Distribution Network Operator (DNO). According to Energy Networks Association specifications, up to 16 amps per phase just needs to inform the DNO. Under Energy Networks Association standards, type-tested systems of up to 16 amps per phase can simply notify the DNO. Larger systems generally need approval before connecting and may face an export limit.
In Great Britain, the Smart Export Guarantee (SEG) requires larger electricity suppliers to offer payment for exported low-carbon electricity. Solar installations up to 5MW can qualify if they meet the eligibility criteria, including certification, and have a meter that records exports. Suppliers set their own rates, and an export tariff does not have to come from the company that supplies the building.
Battery storage keeps more of the surplus on site. The battery charges when generation exceeds demand and discharges when output drops. This raises self-consumption, the share of solar output the business uses itself.
What It Means for UK Businesses
The worth of solar plants on location is highly dependent upon the time at which the company uses electricity. Locations with high demand for electricity during the day include offices, industrial plants, stores, and warehouses. A business that is busiest in the evening will export more unless it adds storage.
On the physical side, south-facing roofs give the highest output, and the structure must be strong enough to carry the panels. Comparing the site's consumption data with estimated generation is a sensible starting point, because it shows how much of a solar power plant's output the business would use.
Frequently Asked Questions
1. Do solar panels work in winter?
Yes. Reduced sunshine and low angle of the sun imply lower production compared to summer. Low temperatures do not affect solar panels' functionality since cold temperature increases their efficiency.
2. Do solar panels work during a power cut?
Not usually. Connected to the grid systems automatically shut in case of failure of the mains supply in order to avoid any risks for engineers working on it. Backup power supply needs special design.
3. Do businesses need planning permission for solar panels?
Not necessarily. In England, solar panels on non-domestic buildings and land can be permitted development, subject to limits and conditions. Wales, Scotland and Northern Ireland each have their own rules.