Oxford Brookes, Sunset, Solar PAnels, Salix Finance

A Hub of High Efficiency at Oxford Brookes University

Oxford Brookes is one of the UK’s leading modern universities with an international reputation for teaching innovation and excellence. They are also in the top tier of universities leading the way when it comes to limiting their effect on the environment*. Their 35% reduction in carbon emissions since 2005, already puts the university ahead of its 2025 target of a 34% reduction, but this hasn’t stopped Oxford Brookes wanting to push on and do more – to continue to reduce its environmental impact and create a student campus that truly supports sustainability, as well as inspiring students to significantly reduce wasted energy use and carbon emissions.

 

Funding and Fusion 21

When Oxford Brookes learned they could secure project funding through Salix Finance (interest-free funding for the public sector to improve energy efficiency, reduce carbon emissions and lower energy bills), the university was keen to increase its existing solar PV capacity and looked into procurement routes to find the perfect solar PV partner.

They discovered Joju Solar through the Fusion 21 public sector procurement framework and after surveying the university site, we helped to identify five more suitable buildings for solar PV – designing and procuring the best possible system within Salix funding parameters. The project couldn’t cost more than £222 per tonne of carbon saved (over the lifetime of the project), with a project payback of 8 years.

 

A greater yield with SunPower

As Oxford Brookes University was committed to generating as much as possible in the available space, to “do more with less” and get the most value from existing building spaces, we used high efficiency SunPower modules on the Buckley Building, John Payne Building, Lloyd Building, Sinclair Building and the International Centre.

Although rare for a commercial project, these state-of-the-art panels gave Oxford Brookes greater output per square metre of roof space, adding just under 300kWp and doubling their solar PV capacity. From a cost perspective, this approach still worked within the Salix Finance funding model, so it was a winner all round!

Despite the installation being initially postponed due to Covid19, the 700 panels were installed in November 2020 and it was an absolute pleasure working with Oxford Brookes University to extend their visible commitment to a low carbon future by creating a high efficiency array – generating 224,912kWh per year, with a 57 tonnes CO2 saving.

 

Discover more

  • We love working in the education sector and Solar schools is one of our specialities.  We can deliver fully funded installations across your school or university estate, so do find out more about our solar for schools and education
  • Discover more about Solar PV and how we can help you.
  • SunPower modules are the state of the art – offering efficiencies of more than 23%.
Salisbury Cathedral, solar, spire

The Salisbury Cathedral Solar Roof

How did a small local community energy group end up building one of the most iconic renewable energy projects in the UK?  Well, it turns out dedication, perseverance, and a little good fortune are all you need.

Salisbury Community Energy

Salisbury Community Energy is a relatively new community energy group.  They were formed in 2017 by a group of Salisbury residents who were trying to address climate change within their local area.  Director Caroline Lanyon explains “When we started we had a simple question: how can we get more renewable energy in Salisbury?”

From small beginnings …

In their early years, Salisbury Community Energy looked at a wide range of possible projects, and all possible renewable energy technologies.  They finally settled on developing a solar power portfolio, as potential hydropower schemes on rivers in the City looked complex due to Environment Agency concerns about the flood plain, and potential opposition from local anglers.

The group started scoping out a portfolio of solar PV projects in Salisbury, mainly on local schools, but with other large community buildings also considered.

Solar on Salisbury Cathedral?

Almost inevitably, someone suggested that the group should approach Salisbury Cathedral about the possibility of installing solar panels there.  However, the group didn’t expect much of a response.  “Local environmental groups had been pushing for the development of a solar array on the Cathedral since the 1990s”, said Caroline “But they’d always been refused”.

But as a new group, Salisbury Community Energy thought it was worth a shot, and they decided to try the door one last time.  To their surprise, it opened!

The Planning Process for Solar on churches

Canon Treasurer Robert Titley from Salisbury Cathedral was instrumental in making the scheme happen. As a local community group, Salisbury Community Energy found a receptive ear as Robert was already implementing a range of green initiatives across the Cathedral, including draft-proofing the medieval building, moving to a green tariff energy and installing LED lighting.  His faith and environmental vision went hand in hand.  “We are called to preach good news, and through this we are taking another small step toward being good news for God’s earth and not just part of the problem”.  Solar panels were an obvious next step, and the idea of a high-profile project appealed.  “It’s important to send a message to the rest of the city”, he added.

At around the same time, the Rt Rev Nicholas Holtam, Bishop of Salisbury was appointed the Church of England’s lead bishop for the environment.  He has recently signed a letter to the Government asking for the environment to be part of its post-COVID-19 plans.  He was naturally fully supportive of the idea of putting solar panels on the Cathedral.

However, before the project could happen, the proposal needed to pass through ecclesiastical planning.  Town planning rules cover development on most churches and local council planning departments adjudicate on them.  But as a Cathedral, especially a unique historical one, the proposals had to pass the scrutiny of church bodies instead.  As one might imagine, it is not an easy process to pass through the many internal committees.  They are very stringent, and rightly so – they do, after all, have a duty to protect these buildings of national importance.

Eventually, the scheme was approved, subject to specific design criteria being met:

  • The panels must not be visible from the ground, or higher ground in the Salisbury area
  • There must be no drilling into the historic structure of the building
  • There must be no damage to the lead roof covering

But just as the project was gaining traction – a new hurdle appeared.  The Government planned to remove feed-in tariffs in April 2019, leaving just months to get this project, and other schools in the portfolio pre-accredited.

The Salisbury Cathedral solar design team

Salisbury Community Energy approached Energy4All’s Schools’ Energy Coop for advice.  They had years of experience in pre-accrediting community energy sites. They agreed to help with early project development stages, such as gaining EPC certificates.  They also managed the financial raise for the scheme when it went eventually ahead.

And this is where Joju Solar joined the team!  As the long-term installation partners for the Schools’ Energy Coop, we were asked to come up with a design that met the ecclesiastic planning committees stringent design requirements.

The project team chose the cloister area for the solar panels. The panels are not visible from the ground, and there is a parapet wall surrounding them.  This helps keep the panels hidden from view but does give local shading issues.  The church left some dummy panels on top of the cloister roof for several months before the build to see if these would be visible from the surrounding area.  It turns out they weren’t!

Because no direct fixings were possible, we decided to use panels mounted on a ballasted frame.  As a roofing material, lead is quite unique in that it is soft, and it moves around a lot as it expands and contracts in the sun.  Clamping on to the ‘broom handle seams’ is not a possibility as it would soon cause a hole around the fixing points.

Joju decided to work with solar mounting system specialists Sunfixings on this project.  Sunfixings have extensive experience in designing solar PV mounting systems for lead roofs and were an obvious technology partner for this project.  The roof has a stepped surface, and is generally a little uneven and not quite straight (it turns out our laser lines are more accurate than 800 years old craftsmanship).  The design team settled on a fully adjustable frame to ensure there was good contact at the right places over the surface of the roof.

It’s not just the panels; of course, there is also the wiring to consider.  The cables were collected under the array, then ran in a discretely positioned basket tray, on rubber feet, following the line of the roof.  The wires ran to the new café and gift shop section, which as a modern extension meant we could finally drill a hole to get the cables to the inverter and consumer unit inside.

Salisbury Cathedral’s Solar Roof

The solar array was finally built on the Cathedral in July 2020, as soon as we were able to come out of lockdown safely.  The system features 37kW of high-efficiency Sunpower 400W modules.

The system was formally opened by The Bishop of Salisbury.  His words, perhaps best sum up the scheme:  “The Church of England is working hard towards a Net Zero carbon footprint by 2030. I am delighted that Salisbury Cathedral is making a contribution that takes us towards this. With clear purpose and helpful partnerships even iconic buildings can make a difference towards sustainability. In these strange times the possibilities of living differently seem all the more important and this project even more significant.”

So, was this iconic project all just a stroke of good luck?  Did it only get built because the community group approached clergy who happened to be passionate about the environment? And then chanced to meet other partners to help with the financial raise, project development, design, and build?

Or maybe we all make our own luck, and the more we try to make our visions a reality, the more likely we are to find others who feel the same way. And then great things can happen. We like to think so, and we expect to see more historic buildings sensitively incorporating solar over the coming years.

 

All photos by the sublime Ash Mills.

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Sunpower, Tesla, Powerwall2, installation

Robert Llewellyn’s Home of the Future

Comic actor and TV presenter Robert Llewellyn is a passionate proponent of new energy technologies.  He runs a Youtube channel, called Fully Charged, looking not just at electric vehicles, but also the way in which that electricity is generated from renewable sources.  If you’re not following it, we thoroughly recommend you do – it really is the best source of news about new energy technologies out there, and puts mainstream media to shame!

Why did you chose solar and storage

Robert Llewellyn has had solar PV on the roof of his house in the Cotswold for some years, but has increasingly felt he could do more.  “I’ve had solar since 2011 and as soon as you have it, you want a battery. In theory it makes so much sense and for once in life the practice proves the point

The design challenge

Robert is of course, also passionate about his electric vehicles, which also need charging at home.  Our brief, therefore was to boost his solar generation, utilise a greater percentage of the solar electricity on site and use any excess to charge his cars.

The Home of the Future

We upgraded Roberts existing solar PV system of 2.5kW conventional modules to 16 high efficiency Sunpower 327 modules, totalling 5.23kW.  These high efficiency modules (over 21%) have doubled the generation from his roof space.

In order to use more electricity onsite, we installed one of the first Powerwall2 battery systems in the country.  This Tesla solar battery unit is much larger than conventional battery units holding an impressive 13.4kWh of energy.  This greater battery capacity matches to the larger PV system – anything smaller would fill up too quickly.

The system works by using excess solar electricity to charge the Powerwall2 during the day.  It discharges in the evening to loads in the house, but by midnight, we do not expect the battery to be empty.  It is at this point that the Powerwall2 discharges into Robert’s car batteries.  The car batteries then fill any remainder with cheaper night-time tariff electricity.

This approach is perfect as the battery is completely empty the next morning ready to capture the maximum possible solar energy through the day.

It is slightly unconventional to do charge a battery (Powerwall2) and then discharge it into another battery (vehicles), and thermodynamically this might not seem sensible.  It is, however, the best thing to do economically.  Robert uses his free solar electricity first, then cheap night-time electricity, with any remaining (on poor days in winter) coming at standard day rates.

Early results seem very promising: “I’ve had the system running for 2 days and my mains electricity usage has reduced by 95%.  Okay, it’s summer, it’s sunny, and over the year I’m sure it won’t manage that, but it’s obvious it will reduce our overall demand on the grid by a substantial amount and utilise far more of the power the panels produce.”

We think this is a perfect exemplar of integrating solar generation, storage technologies and electric vehicle charging.  It is complex, from an engineering standpoint, as we have to balance PV capacity, battery storage capacity, loads in the house and electric vehicle loads, but we look to have found an optimal solution.  The home of the future is increasingly going to incorporate all these technologies operating in combination.

One happy customer

“Joju Solar have been patient and supportive throughout the install of my new solar array and Powerwall 2 battery system. They needed to be patient due to my constant faltering, budget anxiety and ridiculous schedule.  They fitted the battery in a day, wired it up, stayed longer than expected to make sure it was all working, left the place spotlessly tidy and did a very fine job.” – Robert Llewellyn

 

Further reading

  • We’ve developed a free guide to Tesla’s Powerwall2, so you can understand if it is the right option for you.
  • You can see the installation process for Robert’s Powerwall2 in this technical blog
  • The high efficiency Sunpower solar modules are essential to make this system work. Here’s our guide to the most efficient modules on the market