Harnessing the sun with the first Solar roof in Britain

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23 years ago, 100Green were considered pioneers of the sustainable energy market and were just one of a small handful of suppliers who offered green tariffs – and we are proud to still be at the forefront as the UK’s only supplier of 100% green gas. Now of course you’d be hard pressed to find a supplier who didn’t supply at least a small percentage of renewable electricity.

But whilst we may have been supplying renewable electricity for 23 years, one of our longest standing customers has been generating her own electricity for almost 30 years. Professor Sue Roaf is a true trail blazer in the field of home-generation, having made the extraordinary decision in the early 90’s, as a single mum of two, to build Britain’s first solar roof.

We are incredibly proud to be Sue's green energy supplier of choice, having built a trusted relationship over 20 years. We buy her excess home-generated electricity and when she needs a little extra, we supply her with 100% green and renewable energy.

This is Sue's story



Climate change in the 90’s

Sue Roaf is Emeritus Professor of Architectural Engineering at Heriot Watt University in Edinburgh. Sitting in the Oxford Ecohouse in North Oxford, Sue explains that her six-bedroom home is largely famous because it has the first solar roof in Britain on it. Sue designed and constructed her home with the help of a lot of friends in 1995 - and next year celebrates the 30th anniversary of this pioneering achievement.

We asked Sue what it was like making the decision to build an Ecohouse in the 1990’s when 'climate change' was just a phrase used by scientists and the odd news presenter.

“In 1992, we had the Rio conference, which was a red flag for many people to say, for goodness sake, we have to do something to help save the climate.“

”People were buying stupidly big cars and living in energy profligate buildings and I thought, well, how about we try and change our lifestyles so we live decent lives, but using minimal energy.”

”So I decided to build the first solar roof in Britain, which I did with the support of lots of friends, experts and building product companies who were excited about the need for positive action to combat climate change.”

The inspiration behind the Oxford Eco House

Listening to Sue talk, we can hear the passion in her voice as she describes how she took inspiration from her time in the Middle East, understanding how communities survived in some of the harshest climates in the world.

”I spent 10 years from the mid-1970s to the mid-1980s in Iran and Iraq in two of the hottest desert countries in the world. I'd also lived with nomads on their long migrations through the mountains of South Western Iran. These nomads, they live in tents and move from summer quarters in cool high mountain pastures to winter quarters of the warm plains below. And they use no energy and yet they are among the first people on the planet to lose their homes and lifestyles because of climate change.”

We asked Sue how these learnings from one extreme environment thousands of miles away have been manifested as a low-emissions home in leafy Oxfordshire, England.

"This building is designed to use minimum minimal energy in winter and summer.” Sue explains. “In winter, you have to be able to shut everything down and harvest heat from the sun through windows and the two story sun space and store it for later use in the thermal mass of the walls. In summer you have to dump excess heat, either out of the windows using cross ventilation or up and out through Velux windows in the roof using stack ventilation.”

“I'm using sunshine to keep the building warm in winter. The sunshine, coming in through the windows, including two V-lux windows on the top floor, fall on the heavyweight walls and they heat those. There's so much thermal mass in this building, [it can] store heat for a month!”

"In the increasingly hot summers I shade the first and second floor French doors using a balcony and an overhanging roof. To avoid the worst of the summer sun and to protect the house from excess solar gain there are no windows on the Western wall. Last summer I went the next step and fitted a retractable external timber blind over the roof of the sunspace which has made a great difference to how hot it gets."

Doing well by doing good

Solar panels have gradually increased in popularity over the last 30 years, but we know that people are still put off by the up front investment required. At 100Green, we recently surveyed 2000 people and discovered that an overwhelming majority of people (81%) would consider installing solar panels or heat pumps if there were better incentives to improve the efficiency of their homes.

Sue is adamant that her investment and the risk she took to build her Ecohome in 1995 are still paying off today… in fact she is benefitting more as time goes on.

”I'm 72 now,” Sue explains, “and I built this house when I was 42, 30 years ago. I was passionate about the need to take action over climate change then, and still am. I really wanted to help save the world and make a difference. Architects, some of them said, ‘oh, that's just green bling you are sticking on the house.’ No, for me it has been the difference between when you're retired being able to afford enough energy to keep warm or cool enough… and not being able to.”

”It’s the old thing about doing well by doing good”, Sue continues, “because I made that huge effort to build this first solar roof in Britain for the greater good. But now as I've retired and I'm counting my pennies more, I realize that that one investment was probably the best investment I ever made.”

How much does it cost to power and heat the Oxford Eco House?

This is the question we know people want to ask. After all, the Ecohouse is a six-bedroom house which, Sue accepts, is not within everyone’s reach to own such a property. However, what Sue is demonstrating is that a decision she made to throw everything into building her home then is now paying off. Sue was a single mum of two who was inspired to do something good and by leveraging the people, the knowledge and resources she had around her, she is now able to be energy sufficient for a large part of the year.

“Now you won't believe this solar roof cost about £28,000 to build in 1995." Sue explains. "Today you can buy the same solar photovoltaic array for about £4K or £5k.”

”I pay on average over the year just £40 a month for electricity” Sue tells us, “I only pay standing charges over the summer months for both electricity and gas as my hot water comes largely from solar hot water panels for at least six months of the year. Then in winter, when I need more, particularly around December, when the house is full, I will import more energy."

"I have had a long-term and trusted relationship with a 100Green. I've been using them for over 20 years now. They supply genuinely green energy back to me and importantly don't go bankrupt when global prices change. Now they've kept my standing charges stable for two years which makes a real difference to my bills.“

Advice for anyone wanting to live more sustainable lives

Sue shows us around her home and her garden, explaining how each area has been designed to help her live as sustainably as possible. The enthusiasm radiates from her every pore, almost as if this is the first time she is explaining how it all works – which of course is not the case as many have come to visit her and hear her story over the last three decades.

It’s when we ask her how other people can take inspiration from her life and the decisions she has made, that she speaks with even more conviction and passion.

”My advice to you, is put aside the 20th century idea that it's all about energy efficiency.” She goes on to say, “The new movement, the new direction of travel is towards energy sufficiency. And this is a combination of the building, the climate and your lifestyle.”

“In the old days, when I was a kid, you'd go into the warm room in the house to do your homework - you'd use different microclimates around the house. We will have to go back to the old ways and at least have one nice warm room for winter and one nice cool room for summer. Start with that, start small."

The future is about energy sufficiency; develop your home and lifestyles to run the building on free, clean, local energy for as much of the year as possible and use heating and cooling when really necessary.”

We leave Oxford feeling inspired. Sue’s story is unique and fascinating. Even for those of us who may not be considering installing a solar roof, there are many lessons to be learnt from someone who has achieved what could be considered as ‘eco-utopia’.

Sue is proving that it is possible to de-couple yourself from fossil fuels in the 21st century. And at 100Green, we hope that over the next 30 years, more and more homes will be built in this way – putting energy sufficiency at the heart of every home design.

Interested in how more of our energy is generated? Meet Stephen, our dairy farmer from Norfolk who generates his own electricity using biogas, made by the process of anaerobic digestion. Find out more