By Dr Anthony Lewis
Anthony is Chair of Windsor Humanists. In this article, he highlights that renewable energy will reduce emissions but will significantly impact our landscapes. Global investment in electricity infrastructure is soaring, fuelled by the falling costs of renewable energy and the transition to a sustainable electric future. It is imperative that any resulting damage to our ecosystems is minimised. It would be ironic if our drive to decarbonise ends up industrialising our remaining unspoilt wilderness areas.
As laid out by the Intergovernmental Panel on Climate Change in their 2023 Report, there is a clear scientific imperative for us to decrease significantly our CO2 emissions by reducing our reliance on fossil fuels. They conclude that “Human activities, principally through emissions of greenhouse gases, have unequivocally caused global warming,” and “Global greenhouse gas emissions have continued to increase, with unequal and unsustainable energy use, land use and land-use change.” There is, therefore, a clear, unambiguous scientific consensus that we have to wean ourselves off our use of fossil fuels by using more sustainable energy sources. The transition to renewables will reduce our CO2 emissions, but extracting and storing the Earth’s wind, water, atomic and solar energy resources will also significantly change how we use land.
The cost-effectiveness of renewable technologies
There has been an ongoing revolution over the last two decades in terms of improving the effectiveness and cost competitiveness of both renewable energy and in related battery storage technologies. The costs for most forms of sustainable energy have declined rapidly, especially over the last ten years as illustrated in the graph below. The cost of generating electricity using most forms of renewable energy – whether from hydroelectric, solar, wind turbines or nuclear power – all now lie within the same price range in terms of $/KWh (dollars per kilo watt hour) as that for fossil fuels. As a result of these relative cost reductions the use of renewables is now exponentially rising (see graphs). The expansion of renewable energy is likely to accelerate significantly over the next decade and the technologies and engineering will continue to improve based on ‘real world’ operational experience driving further technological innovations. The 2020s are therefore poised to become the decade when renewable energy finally ‘comes of age’ and begins to overtake and replace our use of fossil fuels, especially for electricity generation.
Repurposing our homes with solar energy
The ongoing reduction in the cost of solar panels and small-scale battery storage means that it is now cost-effective to install solar panels on the roofs of our homes in the UK. This is something we did early in 2024 on the south-facing roof of our home in Windsor, for an outlay of about £11k with an economic payback of seven years. Our system has outperformed its predictions and we were ‘off grid’ for most of last year despite the poor summer. We were even able to export our surplus electricity back to the grid when our electricity generation exceeded our usage, earning us some additional income from British Gas. So although it will take seven years to recoup the installation costs we have already seen an immediate and welcome large reduction in our electricity bills, whilst also reducing our carbon footprint. This is an example of the practicable repurposing of land to generate sustainable energy which is already being used as a dwelling.
I was bragging to my neighbour, who is an electrical engineer, that I was proud to be doing my bit to reduce our household CO2 emissions. However, he burst my self-satisfied bubble by pointing out that he had read ‘somewhere’ that as my solar panels were manufactured in China using mainly coal-fired electricity then we would not be ‘net zero’ in terms of CO2 emissions for 20 years. To say I felt deflated and dismayed after forking out £11k was an understatement. However, a quick Google search provided me with the re-assurance I needed. Based on the IPCC 2014 Report, rooftop solar panels emit about on average some 41 grams per kilowatt hour of lifecycle emissions of CO2 with an emissions payback of about three to four years. Based on these figures, which take into account the global energy mix in 2014, I am happy that our domestic solar panels have significantly reduced our personal carbon footprint whilst also saving us money and now represent a great investment opportunity for all of us, with an economic payback of seven years and a ‘net zero emissions’ payback of less than four years (see footnote 1 below for more details).
The land footprints of different energy sources
Our experience with installing solar panels illustrates that no energy source comes without environmental impacts in terms of its direct lifecycle CO2 emissions, changes to existing land use, the need for raw materials and other resources, and all come with different but often significant impacts on wildlife and existing human activities. For example, the batteries in our attic and the rare metals used to dope the silica in the solar panels both require mining and chemical processing to produce the materials required for the efficient generation and storage of electricity. Renewables will, therefore, have an enormous impact on our landscapes as the developments have to be at a sufficient scale to be able to capture and store sufficient amounts of the Earth’s and Sun’s natural energy resource to meet our total energy needs. This will unavoidably create tensions with existing land use and result in the emergence of new environmental pressures and challenges. Some consider huge solar arrays and onshore wind farms as another type of re-industrialisation of our landscapes. It is clear that care will have to be taken to minimise any negative environmental impacts. There is a lot of misinformation about these implications as illustrated by the comments by my neighbour about the ‘net zero emissions’ payback time for our rooftop solar panels! So let's explore some of the issues based on some solid data and assessments.
This logarithmic plot of land impact attempts to shine a light on some of these issues. It illustrates in broad terms the relative lifecycle CO2 emissions in g/KWh (grams per kilowatt hour, derived from the IPCC 2014 Assessment) and the total land footprint of each type of main renewable energy source in m²/MWh (square metres per megawatt hour derived from the 2021 Report of the United Nations Energy Commission for Europe from Our World in Data website – refer to links below for details). The matrix separates out the relative efficiency of land use for the amount of electricity generated by different energy sources plotted against their overall total lifecycle CO2 emissions. The plot provides some interesting and perhaps surprising insights into the varying impacts on our landscapes by different energy sources.
The high emissions and high land impact of coal
Coal sits at the top right of the chart as it has a high land impact and very high emissions of CO2 and other noxious gases and chemicals. Coal is by far the most polluting energy source. It is also one of the most inefficient in terms of land use and most destructive due to the impact of opencast and subsurface mining. And yet coal use is still expanding appreciably worldwide, driven by the energy needs mainly of China and India (see the graphs from Our World in Data below). This increase has been one of the main drivers of the continuing increase in total global CO2 emissions. This is despite China taking a lead in both solar and wind energy. This relentless increase in the use of coal is currently sabotaging the reductions of CO2 emissions delivered by other countries through their increasing use of renewable energy. From the attached graphs it can be seen that consistent reductions of absolute CO2 emissions levels have so far only been achieved mainly in Europe and North America. It may surprise some that the US leads the way with the largest absolute reductions due to its move away from coal to “cleaner” gas as part of its energy transition.
I cannot have been the only person dismayed by the political focus of the recent COP29 2024 Conference in Azerbaijan on the issue of “reparations” for historic CO2 emissions, rather than on the practicable need to bring our global use of coal to zero as quickly as possible? We have been aware of the increasing impact of our fossil fuel CO2 emissions on the climate since the early 1990s so there really is no reason for our use of coal to continue to accelerate as it is doing at present. Especially given that renewable energy and related technologies are now cost competitive against the use of fossil fuels. It can legitimately be argued that the “net zero” focus that should be our main concern is achieving “zero” use of coal as quickly as possible given this would have the largest and fastest impact on reducing CO2 emissions.
The industrial footprints of onshore wind, solar arrays and hydro energy
Solar land arrays, hydroelectric installations and onshore wind farms all have high land impacts and they all sit in the bottom right hand box of the land use matrix above. They have significantly lower CO2 emissions than fossil fuels, but even here there are variations for different renewable energy sources. Solar energy emits the most lifecycle CO2 of all the renewable energy sources due to its more complex supply chain and manufacturing processes which require mining of the raw materials for both batteries and solar panels. Wind energy has the lowest emissions which arise from the mining and manufacturing of the steel and the use of cement for the installations. Hydroelectric power has lifecycle CO2 emissions that sit between that of solar and wind power, due mainly to the cement used in dam construction. The impact on the countryside also varies for these three renewable energy sources as follows.
Onshore Wind Farms have the largest impact on the landscape. This varies enormously depending on the height of the turbines, their distribution (tight or sparse packing), human population density, the need to build additional export infrastructure such as interconnections or pylons to export the electricity for remote locations, and the effect of all of this on current land users and the overall environmental impact. About five years ago, I played an active part in stopping the installation of a very large proposed wind farm on top of the Binevenagh mountain in Northern Ireland, where I grew up (one of our campaign posters is attached). The mountain is a designated area of outstanding natural beauty (termed an AONB). The area contains numerous nature reserves and areas of scientific interest. It forms an integral part of the Giant's Causeway Coast tourist area and is featured in the Game of Thrones television series. The area has an iconic beauty which was euphemistically termed a “visual amenity” by the US Renewable Company that was proposing the development. We succeeded in scuppering this particular proposal but it illustrates the real dangers that in a crowded island such as the UK that we have to guard against the indiscriminate location of large wind farms across our wilderness areas that up to now have escaped industrialisation. I am a strong supporter for the need to reduce our emissions and was dismayed to find myself being labelled a “NIMBY” (Not In My Back Yard) by advocates of this particularly ill-considered development. This experience, however, does demonstrate that we have to ensure that all onshore wind farms are located wisely, taking into account any associated new infrastructure that is required and their total environmental impacts on the landscape.
Hydroelectric power also has a large land impact due to the damming of river systems to create artificial reservoirs. Hydro is the most mature renewable energy source led by Norway which generates over 90% of its electricity from hydro installations followed by Sweden (nearly 70%) and Brazil (over 60%). Its use is constrained due to the need for appropriate topography in areas sparsely populated where it is feasible to flood large areas of land. In addition, hydro can have a significant detrimental impact on the downstream ecologies of entire river systems as China has discovered, which restricts its overall future potential.
Solar Land Arrays have a land impact that varies depending on the size and packing of the arrays. As we have seen above, solar panels are feasible even in the UK where sunshine is never guaranteed. Relatively small scale land-based solar arrays have been installed in the UK where farmers can continue to farm and graze their livestock. Elon Musk pointed out in 2015 when launching the Tesla PowerPack batteries that a 100km x 100km solar array located in an unpopulated desert area like Nevada could generate a total of up to 500 gigawatts of electricity per year which would be sufficient to meet the total annual electricity demand in the USA of about 425 gigawatts. The concept is scientifically sound and based on the work of Andrew Smith at the Energy Institute at the University College London (for further information please refer to the links below). This means that a few mega-arrays built in the Earth's deserts, which wrap around the mid latitudes both north and south of the equator, could supply all our global electricity needs. However, the building of such huge mega-arrays raises important geopolitical concerns around security of supply. They would also need significant new infrastructure requiring the installation of huge pylons and subsea interconnecters to export the electricity to the main centres of demand. The USA could perhaps reliably use their desert areas but could Europe risk relying on its electricity from large arrays sited in the Sahara Desert in North Africa?
The low land impact of rooftop solar, offshore wind and nuclear
Rooftop solar panels, offshore wind power and nuclear have the lowest impact on land use and low CO2 emissions and sit on the bottom left of the matrix. As already mentioned, there is currently a boom underway in the UK, Europe and in the USA in the placement of solar panels on the roofs of new and existing buildings, and other “brownfield” sites. For example, Switzerland is experimenting with using solar panels placed between their railway tracks. The existing electricity grid can usually cope with such smaller scale geographically dispersed solar arrays without the need for major upgrades to network infra-structure which further reduces their impact on land compared to the larger more industrial solar land arrays. Offshore wind and nuclear also have low land impacts but these are caused by different factors to rooftop solar as follows.
Offshore Wind Energy has both a low impact on land and low CO2 emissions. These emissions are related to manufacturing of the turbines and export infrastructure, and the cement used in their installation bases. Wind farms are especially well-suited to maritime countries surrounded by shallow seas. The British Isles is an ideal area given its location on the continental shelf of NW Europe where there is reliable wind most of the year. The UK, as a result, is one of the global leaders in offshore wind farms, together with China and Germany. In 2024, the UK generated nearly 50% of its electricity using offshore wind and was able in the same year to close down its last coal-fired power station. In 2025, there are several very large offshore installations due to come on stream in the UK which includes the largest offshore wind farm ever built on the Dogger Bank in the North Sea. The UK is embarking on a massive upgrade to its electricity grid to link the new areas of energy supply from these offshore wind farms to the centres of demand. For example, the UK National Grid announced at the end of 2024 an ambitious £35bn programme to upgrade the UK transmission cables and pylon network over the next 10 years. This will have an impact on the UK landscape – particularly in areas close to the new mega offshore wind installations.
Nuclear has the lowest land impact of all the renewables but often gets forgotten in discussions about ways to reduce our use of fossil fuels. Modern small-scale reactors have been developed which generate significantly less nuclear waste than earlier nuclear plants built after World War Two. China has just commissioned an innovative small-scale reactor, the novel design of which has eliminated any risk of a catastrophic meltdown as occurred at Chernobyl. At present, gas and coal-fired power stations are used for the generation of electricity as “marginal swing producers” due to the intermittent, unreliable nature of solar and wind energy. Nuclear, at present, represents the only viable low carbon substitute energy source that has the required scale and immediacy that is required to operate as the back-up supply at short notice to address the “intermittency” of the supply of electricity due to the unreliability of the UK’s weather.
The global challenges
Investment in electricity infrastructure is soaring worldwide due to the plummeting costs of renewable energy sources driven by ongoing rapid technological innovation. This marks a pivotal moment in the global effort to mitigate climate change and CO2 emissions through reducing our use of fossil fuels. The demand for electricity is likely to surge even more, driven by our increasing use of electric transportation, heat exchangers and decarbonisation of our industrial processes. Low carbon renewable energy sources such as solar, wind, hydro, and nuclear energy all present significant challenges with respect to their impact on the landscape, wildlife and existing human activities. Balancing the different environmental footprints of renewable infrastructure will present challenges as ever larger solar arrays and wind farms are installed at an increasing pace worldwide. Each country will have to take into account land availability, environmental constraints and the social impacts of large-scale renewable projects, which will require careful stewardship of the natural and human environments that sustain us.
The evolving energy supply mix for each country will be dictated by the local availability of their natural resource such as wind, sun and hydro provided by climate, location and topography as illustrated in the graphs above. Each country will seek to ensure their own security of supply that meets their increasing demand for electricity. Also, nuclear power will have to be part of the energy mix. This is because it is the only low-carbon energy source which can currently be used as the swing producer, to replace the current use of gas and coal for this purpose. For this to happen, public perceptions about the use of modern nuclear power technology will have to improve. The earth's deserts are also a potential reliable source of solar energy where a few large arrays strategically located around the earth's desert belts could, in theory, provide all of humanity's future energy needs. However such solutions would present countries with obvious risks to their security of supply. This illustrates how our efforts to decarbonise will increasingly present us with geopolitical challenges and societal pressures as the energy transition continues.
Conclusion
It is clear that the increasing use of renewable energy will dictate major changes to our use of land. It is imperative that this is done in ways that seek to minimise the disruption to our ecosystems and communities. It would be ironic if our drive to decarbonise our economies means that our remaining unspoilt wilderness areas become irreparably industrialised or causes other unforeseen damage to the natural environment or restricts the breadth of current human activities.
Useful links
IPCC Climate Change 2023 Synthesis Report - Summary for Policy Makers
How Does the Land Use of Different Electricity Sources Compare? Our World in Data 2022
CO2 Emissions by Country by Hannah Ritchie and Max Roser 2024 in Our World in Data
A New Electricity Supercycle is Underway Economist 5th January 2025
Low Carbon Electricity Generation by Country from Our World in Data 2021
Solar Power by Country by Kayla Zhu 2024 on Visual Capitalist Website
What is the Carbon Footprint of Solar Panels? By Sam Wigness 2023 at the Solar Learning Centre
Electricity Generation from Solar from Our world in Data 2023
Sun Machines The Economist June 2024
Wind Power by Country by Dorothy Neufeld 2024 on Visual Capitalist Website
Offshore Wind Power Wikipedia
Elon Musk’s plan to Power the US using Solar - Inverse article in 2020 by Mike Brown, and, University College London Energy Institute Blog by Andrew Smith 2015
China Energy Analysis by Lauri Myllyvirta 2024 from CarbonBrief website
Footnote
The 41 g/KWh figure for lifecycle emissions for solar power was taken from the Sam Wigness article at the Solar Learning Centre based on the IPCC 2014 Report (see links above). Since 2014, China’s proportional reliance on coal fired electricity has remained at around 55% so the 41 g/KWh figure remains valid. As China increases its use of renewable energy these lifecycle emissions for solar panels should continue to reduce. However it is a rather complicated picture as China’s use of coal is actually increasing in absolute terms, despite staying constant at about 55% in relative terms. This means that any future improvements in the lifecycle CO2 emissions for solar energy may not occur as fast as they could.
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