ANALYSIS - Utility solar promotes enlightened approach to land use

Following the completion of Europe's largest floating solar project, and the latest mega solar installation on a former golf course in Japan; this month's article focuses on innovative approaches to land use.

Utility solar promotes enlightened approach to land use

In overall terms the land area required for solar power systems is not a constraining factor. On average, the world's electricity supply could be generated by solar arrays covering just 0.03% of the total land area. Even in the densely populated less sunny parts of North West Europe, this only rises to a maximum of 0.26%, while Japan would need 1.22%. Given that a significant proportion of solar power is actually installed on rooftops, the pressures on productive land are even lower than this.

However, there are economic and technical benefits in installing generation near to the more populated areas. Solar developers and legislators have therefore been addressing ways to minimise the effect of utility scale solar projects on the availability of productive land.

First option – build in infertile regions

In countries where there are substantial areas of desert and infertile scrubland, this is a good place to install solar projects; especially as these regions often have high levels of solar radiation. The largest solar power stations in China, the USA, India and South Africa have all been built in this type of arid region.

Even in these regions development is not always popular. Recently for example, a further lawsuit was filed in an attempt to stop a 247 MW solar project in the Panoche Valley, because of the adverse effect this might have on blunt-nosed leopard lizards and giant kangaroo rats. The other disadvantage of many desert locations may be the distance and cost of transmitting the power to where it is needed.

Option 2 – Brownfield sites and other land redeployment

Many countries and regions may not have access to suitable arid areas, and so need to adopt other strategies to mitigate land-use.

A good place to build solar parks is on brownfield sites, especially where soil contamination or other issues makes them less suitable for other types of redevelopment. There is a growing trend, particularly in Europe and North America, to site solar projects on former landfill sites and quarries.

Many other types of previously developed land are also suitable. A prime example is the use of former airfields, especially as these are typically flat and level. This approach has been particularly widespread in Germany, the UK and France, where many airfields from the World War II and Cold War eras are no longer in service.

Even on active airfields, substantial areas are unused and offer similar benefits for solar projects. An increasing number of active airports, most recently the Indira Gandhi International Airport in Delhi, now host solar projects.

As a densely populated country where much of the terrain is mountainous, Japan has more land-use constraints than most. It has found several innovative approaches to reassigning undeveloped land for solar power projects. Firstly, changes in trade patterns mean a lower volume of goods passing through Japanese ports than in the late 20th Century. Many of Japan's larger solar parks are therefore built near the coast on former dockside areas.

Other approaches – thinking outside the box

The popularity of golf in Japan has declined markedly since its heyday and many golf courses are no longer viable. An increasing number of solar projects are being developed on redundant Japanese golf courses, such as the 32 MW project commissioned in March at Kumenan, Okayama.

Japan is also the pioneer in avoiding land-use altogether by deploying solar arrays on water. Its largest floating solar project at 13.4 MW is being built at the Yamakura Dam in Chiba. This approach is now being followed in Europe, where Lightsource recently commissioned a 6 MW project on the Queen Elizabeth II reservoir near London.

A similar approach has been adopted in India where solar projects are being developed to cover canals. The largest to date is the 10 megawatt project on the Narmada Canal in Gujarat and more canal top projects are now under development. These projects offer a secondary advantage in reducing the evaporation of water.

Minimising use of prime agricultural land

For countries where some use of agricultural land is unavoidable, measures can be adopted to minimise the effects on the best land.

For several years, Germany has restricted green-field development to the borders of roads and railways. You can take a tour of many of Germany’s solar parks without leaving its autobahn network!

The UK discourages solar park deployment on agricultural land if it is within grades 1, 2 or 3a.

Other recent utility-scale PV news

We end as usual with our regular monthly look at interesting and new developments in the last month:

Mexico accepted a reported 1,860 MW of solar capacity in its first long-term electricity tender. A total of 12 solar projects were selected in seven provinces. The plants need to be commissioned by 2018.

NTPC’s 200 MW project at Anantapur was connected in early May to become India’s largest single solar power plant.

The seventh of South Africa’s 60MW+ solar power stations opened in April at Paleisheuwel.

Source of data

All the details in these posts are based on the Wiki-Solar Database of some 5,500 utility-scale PV solar projects around the world. Unless otherwise stated, capacities are expressed in terms of the AC output of the plant, and ‘utility-scale’ is defined as projects of 4 MW AC and over.

About the author:

Philip Wolfe MBE has been in renewables since the 1970’s when he was founder Chief Executive of BP Solar. He led companies in the PV sector until the early 2000’s. Since then he has undertaken more broadly-based roles in renewable and community energy. His book on utility-scale solar was published in 2012.

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