Endless possibilities of solar power investment

International energy experts are waxing lyrical about its endless possibilities, businesses are increasingly buying into it, and the public barely knows about it.

Solar farms are poised to be a mainstay in Ireland as the country transitions from fossil fuels to more renewable sources in the coming decades, and along with wind and hydro-generated power.

While we have heard much about the benefits of heating our homes using solar panels, business owners are now seeing the potential in solar farming.

As more and more finance comes into the burgeoning industry, farmers will be keen to get their share of business from use of their land, as they move away from many traditional agricultural practices now seen to be unsustainable when it comes to emissions.

The basic principle of energy from the sun appears self-evident, but how does solar power work?

According to the Sustainable Energy Authority of Ireland (SEAI), there are two broad groups of technologies which generate electricity from light.

Of these, solar photovoltaics (PV) are the most common solar technologies worldwide, are also the fastest growing in terms of installed capacity, and are best suited for use in Ireland.

Concentrated solar power (CSP) technologies produce electricity by focusing sunlight to produce heat and drive an engine connected to an electrical generator, and are currently found in countries with year round sunshine.

The Irish Examiner asked Tyndall National Institute to breakdown what the public needs to know about solar farming.

The conclusions of Tyndall’s head of energy research and one of the most recognisable academics in Europe, Professor Brian Norton, suggest that solar farming can be an inherently good thing for the country – once the mistakes of previous renewable energy installations are avoided.

Community buy-in and the public being informed at all times, coupled with an accepted framework for farming from a legislative perspective, should mean Ireland can benefit handsomely from the burgeoning solar farming industry, according to Mr Norton.

“Basically solar farms are photovoltaic (PV), which converts solar energy directly to electricity. There are no moving parts, it converts directly. PVs have been going down in price, continually doing so. For example, in very sunny places, they would compete with fossil fuels. They wouldn’t quite be in that position in less sunny places yet, but they are getting that way,” said Mr Norton.

“They have a very broad range of applications, for example, you see a lot of street furniture, such as signs that are powered by solar energy. The reason for that is that it avoids the cost of digging up the street and all the kinds of infrastructural issues that go with it. There is a very particular thing around remote locations, etc. There is a huge range of applications.”

Solar farms are a particular kind of application, according to Mr Norton.

“You can have PV on buildings, you can have them on bus stops, you can have them on watches. You have a range of scales, and solar farms are a very particular scale. The reason why they are interested is that they have the capacity to provide energy into the grid, which then obviously enables one to decarbonise electricity production.”

There is no point in robbing Peter to pay Paul, which is what essentially happens by powering electric transport and systems from a fossil-fuel station, according to Mr Norton.

That is where solar farming comes into play.

“As you are shifting more to electricity, for example for electric cars, which is powered by a fossil fuel power station, you’ve only moved the fossil fuel production from the car to the power station. You need to decarbonise the electricity system, so PVs come into that.”

They should go hand in hand with other renewable sources of energy such as wind.

“Where you look at the load profile as a whole, and this is a very broad and statistical generalisation, when the wind is blowing furiously, it tends not to be very sunny and vice versa. So in terms of a renewable energy source going onto a grid, both wind and solar are variable – they tend to complement one another.

“The other characteristic for both wind and solar in the kind of climate that Ireland is in, is because the weather comes from the Atlantic swirls, it’s anti-cyclonic, then you get the clouds coming in periodic patterns. So if you distribute your resource, it means that the output from any one of those resources evens out.

“That’s why you have wind turbines around the country, it’s why you have wind farms. It’s why you have solar farms around the country. The output for any particular one is evened out because of the distribution around the country. You know it is going to be sunny in summer for example, but you don’t know exactly how sunny it is going to be in a particular hour in August. But you do know probabilistically, and you iron out the probabilities by distributing it around the country. That is the big picture,” Mr Norton said.

An advantage of solar power is that they are strong and durable.

“The systems are the PV array, which is silicon, it’s encapsulated and robust, it isn’t going anywhere soon and lasts a long while. There will be a controller in there and other various bits and pieces of electronics in there. That goes to the inverter, because they produce direct current, and the grid has alternating current, so there is an inverter in the system to produce that alternating current, and then it goes to the grid.

“The lesser reliable components are things like the converter, not the PV array. Assuming there aren’t manufacturing defects at the beginning, they can sail on quite happily. But some of the components have a maintenance and operational requirement to replace things like inverters and other components to maintain the systems and all that sort of thing.

“The solar farms are providing alternating current [AC] largely to the grid. That is quite different from the solar you see on houses, for example, which are increasingly for self-consumption in the house itself, and which would have batteries that would store it as DC for later use. These systems tend not to have batteries. They are supplying the grid.”

They collect both direct and diffused solar radiation, so they work on cloudy days, so they don’t need direct sunshine, according to Mr Norton.

“What is interesting is that PVs get less efficient when they get hot. They get about 0.5% less efficient for every degree of temperature rise. The ones that are in the Sahara desert are working less efficiently because they are very hot.

“They are obviously getting a lot more sun, but they are less efficient. Ones in Ireland produce a lower level of solar radiation so while they have got a lower sun input, they are working more efficiently because they are operating at lower temperatures.”

The issue for solar farms is that they have to be spaced sufficiently far apart so that they are part of the array, he said.

“Cells make up arrays so you have got an individual solar cell that is part of a module that then make up arrays,” says Mr Norton.

“Each part of the array, say going up a hillside or in a field or whatever, can’t shade the one behind it. There has to be a gap between them.

“That means that the vegetation grows between them, and while the ones proposed for Ireland tend not to do this, you can even have solar cells where there is a service on the top where you can collect solar energy, but also a solar cell underneath as you reflect it off the ground, which tells you how much light you can get.

“There is also an activity internationally in combining PV with various kinds of farming because you grow things around them. You might have livestock, sheep or goats, or certain crops or whatever, that you can grow around them. Light will still get amongst them, which is the important thing.”

Biodiversity concern a factor in rows over location of utilities

Clear regulatory environment would go a long way towards assuaging concerns regarding the fast-moving renewable energy industry

Now that we have established the good that can come from solar power, are there downsides to solar farming?

There are, but they can be managed if clarity, transparency, and community buy-in is emphasised, according to Tyndall’s Professor Brian Norton.

“They do need to be near the grid, you obviously cannot be too far away from that. They are not suitable for sites where the amenities rely on visual quality. That rules them out,” he said.

With any technology where you are consuming land, there are competing options for that land, said Mr Norton.

“The obvious one being farming, and other use also. In terms of the analysis, those things need to be viewed very, very clearly, although it should also be said that in farming, there is set aside where land is not used anyway, as it were.

“The nature of the land tends to be on land where there is not another productive use anyway.

“But nevertheless, in terms of the appropriate selection of sites, the environmental impact, wildlife, alternative uses, and so on, all need to be taken into account thoroughly.

“That also should be, and is a requirement in Ireland, subject to appropriate public consultation.

“Solar power is a different resource than wind, although they do complement either, by the nature of its operation. It is silent, which is another important attribute.

“There is that visual factor, if you don’t like the look of them, so a particular location is important in terms of amenity. That needs to be taken fully into consideration when it comes to location,” he said.

A clear regulatory environment rather than interventions down the line — as has been the cart-before-the-horse approach taken by Irish authorities in the past — would go a long way towards assuaging concerns.

“It is better to have a clear regulatory environment to do these things that everyone has to follow, rather than being driven by incentives that are selectively made available to the particular people who happen to get them.

“It does need that proper regulatory environment, such as how on a technical level you send the electricity to the grid. Environmental legislation exists already and things such as environmental impact assessments can be applied directly across.

“One of the interesting things is that it is a technology that is going down in price. If one makes a particular measure that you agree to buy the electricity at a certain price, that needs to have a mechanism for keeping it under review. That margin could increase if future systems are installed, at that same price, despite prices going down. That has happened in some places previously. The regulatory environment needs to be dynamic, have good disclosure around what prices are.”

One of the interesting things about PV (photovoltaics) is the durability, often they are signed up on contracts of a fixed duration to pay back the costs of the system, according to Mr Norton.

“People who are buying the electricity from the installation and over so many years are paying back the cost of installation.

“These are well-designed and well maintained, incredibly durable systems, so that at the end of their lives, they can actually be producing electricity still, when all their costs have been met. The longer they can last and are properly maintained, they are properly reused where possible, and certainly recycled.”

There is a danger of disregarding the good if you are insisting on perfection, Mr Norton warned.

In other words, having too restrictive conditions on solar farming and power could mean Ireland missing the boat while other countries thrive.