Energy, all energy, irrespective of its form, is the most important ingredient of life. It drives all biological processes in the natural world and it drives all activities of modern humankind, from the food we eat to the devices carried in our hands. And our appetite and need for energy is growing at an alarming rate. 

Within the next 30 years the world’s 7.7 billion people will become nearly 10 billion. With such growth we have a responsibility to ask ourselves two key questions:

  • How are we going to feed all of these people? and 
  • Where is the energy required to do so going to come from?

These two questions go hand in hand – you cannot produce the volume of food needed to sustain a population in the multiple billions, without expending a significant amount of energy.

The energy consumption in food production can be broken down into four parts: agriculture, transportation, processing, and food handling. Of these, the agricultural element accounts for around 20% of all the energy required, and is the most important – without the food being grown or bred, the other three parts are redundant. In the United States it has been estimated that getting food from farm to consumer accounts for 10% of that nation’s energy budget.

These are significant proportions and warrant particular consideration when assessing future energy needs and the sources from which it is derived. Coupled with the fact that all human activity has a largely negative impact upon the natural environment, and therefore on its ability to sustain meaningful food production, and you can see how, from a purely self-preservative standpoint, the case for increased reliance upon renewable energy resources is strengthened. 

Solar Farm In The UK

Whether by design or accident, the move towards greater reliance upon renewable energy sources is being clearly exhibited in United Kingdom (UK) energy production. In the last five years, the amount of renewable capacity has tripled while that of fossil fuels has fallen by a third as power stations have reached the end of their lives or become uneconomical to run. Dr Iain Staffell, lecturer in sustainable energy at Imperial College London, has summed up this situation succinctly when he said, “Britain’s power system is slowly but surely walking away from fossil fuels.” However, Dr Staffell has also warned against the reliance upon one source of energy alone, citing the variability of the British weather as reason enough for a diverse and complementary source mix across the board and especially within the renewable space. For example, in March 2018 an abnormally late and long cold snap put extreme pressure on the UK’s available gas supplies, while in June 2018 a long period of warm settled weather across the country resulted in a wind power shortage. 

At present the UK’s source mix sees gas dominant, contributing just under 40% of energy, while nuclear accounts for 24%. The renewable sector now accounts for around 30% and passed a significant milestone between July and September 2018 when the capacity of wind, solar, biomass and hydro power reached 41.9 gigawatts (GW) and in so doing exceeded the 41.2 GW capacity of coal, gas and oil-fired power plants combined. This was the first time that the capacity of renewable energy had overtaken that of fossil fuels in the UK, something that experts said would have been unthinkable just a few years ago. 

In terms of installed and operational capacity, wind is the most significant source of renewable energy at more than 20 GW, followed by solar, with biomass third. The trend is clear and there are a number of new wind and solar farm installations in the pipeline. 

Solar power’s journey in the UK over the past nine years has been inspiring – from generating a mere 20 GW in 2009 to reaching a cumulative installed Photovoltaic (PV) power capacity of 12.93 GW by the end of August 2018. Of the cumulative capacity, 1.51 GW comes in the form of large-scale PV plants over 25 megawatts (MW), while solar facilities between 5 MW and 25 MW account for another 4.51 GW. Installations ranging between 50 kilowatts (KW) and 5 MW have reached a combined power of 3.49 GW.

As for residential and commercial PV, solar power systems up to 4 kW comprise the largest share, at around 2.57 GW of installed capacity, followed by PV arrays between 10 KW and 50 KW (791 MW), and PV systems between 4 KW and 10 KW (226 MW).

Overall, 959,980 solar power generators with a combined cumulative capacity of 12,933.8 MW are currently connected to the grid in Great Britain. Of the residential installations, only about 10,000 currently have installed battery storage. 

Around 45% (5,833 MW) of the cumulative capacity is represented by solar parks exceeding 5 MW in size, while another 20% (2,574.8 MW) come from residential installations up to 4 KW. But with a newly installed PV capacity for the first eight months of 2018 being just 155 MW – a growth rate of around 20 MW per month – the UK experienced its lowest solar growth in 2018 since 2009. For comparison, in the same period of 2017, new PV additions totalled 865.7 MW, while in the first eight months of 2016 and 2015, new capacity reached 1.95 GW and 3 GW, respectively.

The current slowdown, coming against a backdrop of lower solar panel costs and improved storage battery technology, is mainly due to the well known issues in the British solar market such as, amongst others, the exclusion of large-scale solar from the Contracts for Difference (CfD) scheme and the lack of a proposal for a post Feed-In Tariff (FiT) framework from the Department for Business, Energy and Industrial Strategy (BEIS). When in 2016 the FiT incentive was dramatically slashed the financial attraction to householders was largely killed. In April 2019 the scheme closes completely, and without a successor on the horizon the outlook for this segment of the solar sector appears to be bleak. 

However, long term British solar advocates are pinning their hopes for a residential revival on the continuing fall in the cost of panels, and complementary technologies, including household batteries and electric cars. Dr Jeremy Leggett, the founder of Solarcentury, one of the UK’s largest solar companies, believes that the industry is, “In flux but it’s heading in a very exciting direction. We’re coming out of the doldrums, whatever the government does.” While the former oil geologist admits the UK solar market is stagnant, he, like Dr Staffell, is confident that the direction of travel is set – an increasing reliance upon solar generated power. 

Improved household batteries such as Tesla’s Powerwall, enable householders to consume rather than export their surplus solar electricity, which makes more financial sense. Energy suppliers typically sell a kilowatt hour of power to a householder for in the region of 15p, much higher than the 5.24p a solar home can earn for exporting to the grid and the 4.01p for generation under the feed-in tariff. 

While the economics of solar have the potential for significant improvement, few believe that they will stack up in the coming years without some form of continued support and direction from central government. A replacement for the FiT scheme would no doubt form the foundation of such support. But some are convinced that government should go further and amongst other things provide incentives for house builders to incorporate solar energy generation into their core offerings. 

Irrespective of the recent slowdown in both the large scale and residential solar markets, expansion does continue and the amount of solar generated energy will continue to rise and be a significant contributor within the renewable energy sector. However, the inherent variability of generation, coupled with scalability issues, materials and land use, means that this sector alone cannot be relied upon to replace both fossil fuels and ultimately gas too. It is therefore imperative that the UK’s nuclear power generation capabilities are increased and enhanced in a complementary fashion. It is only by harnessing the naturally renewable resources of wind, sun and water with the power generated by large scale nuclear fission, that reliance upon fossil fuels can be radically reduced and ultimately eliminated. 

An energy source mix that does not comprise significant global warming emissions is essential to our farmers’ abilities to produce the volume of food necessary to sustain the growing global population. It is just one of many factors, but one that has the potential to level the playing field just enough to make it a fairer fight. Solar power generation has the distinction of a unique side effect to this cause. In the UK it has been found that solar farms have actually contributed to increased food production and local biodiversity. This is because a large number of solar farms continue to produce food and where it is possible to graze sheep amongst the solar panels, farmers have witnessed the benefits of panels providing shelter during the winter months. Livestock have thrived and have been consequently more productive. 

Sheep grazing under solar panels

Solar power generation has the distinction of a unique side effect to this cause. In the UK it has been found that solar farms have actually contributed to increased food production and local biodiversity. This is because a large number of solar farms continue to produce food and where it is possible to graze sheep amongst the solar panels, farmers have witnessed the benefits of panels providing shelter during the winter months. Livestock have thrived and have been consequently more productive. 

But perhaps of greater importance is the fact that research by ecologists has shown that solar farms demonstrably increase biodiversity compared to farmed or neglected land. Within a short time of building a solar park, they have found that there is a statistically significant rise in the number of bees, butterflies and wild flowers. Such increases inevitably have a positive effect on the productivity of surrounding food producing land. Energy is the principle driver of all life and human activity. In particular, the contribution of solar energy production has been shown to go far beyond its gigawatt output to the national grid. It is therefore not unreasonable to regard solar as the most important of all renewable energy sources currently available to humankind. 

Imogen Mann