Spotlight on solar this Great Big Green Week

The Great Big Green Week has begun. It’s the UK’s biggest ever celebration of community action to tackle climate change and protect nature, and we are right behind it!

Supporting energy change

Community action to bring about climate change, and more specifically energy change, is something we wholeheartedly support. In fact, we built the very first community-funded solar project in the UK, and have been responsible for nearly 10% of all community renewables in the UK – all of it rooftop mounted solar.

We work closely with our friends at Energy4All. It’s a partnership which has helped to bring about some incredible community energy projects, including installing an iconic solar array on Salisbury Cathedral, a 1.3 MW portfolio of community funded installations for M&S, and our 636kWp installation at Prodrive with the Low Carbon Hub. This became the largest community funded roof in the country.



Energy4All work with communities to develop these innovative renewable energy projects. They raise the funds for them to move forward, and we install the solar. We’ve recently finished one such community project and we’d love to share it with you, to celebrate The Great Big Green Week 2024.

Solar schools – Brentside Primary

Let’s shine a light on Brentside Primary Academy, a two form entry academy situated in Hanwell, in the London Borough of Ealing.

We’ve just installed 41.71kWp of solar PV here, helping the school make the transition to renewable energy. It’s part of their efforts to reduce carbon emissions and make the school more environmentally sustainable. With an annual predicted generation of 37,580 kWh and CO2 savings of 7.78 tonnes per year, they are certainly well on their way to achieving their ambitions.



Brentside Primary was keen to swap to solar as it

“takes the pressure off the wider national grid infrastructure, and with the increased demand for electricity, the use of clean, renewable energy has never been more important. We would like to thank Energy4All and Joju Solar for making the project possible”.

Brentside’s solar installation is part of the portfolio of projects made possible by The Schools’ Energy Co-operative – a co-op installing community-funded solar panel systems on schools free of charge, as well as paying all its profits to its member schools. At Joju Solar, we’re very proud to be part of it.



Swap Together 

So, this Great Big Green Week what will you swap? Have you got plans to change the way you generate or consume energy? Are you interested in running your home with solar energy? Does your workplace have a large roof that would be perfect for solar panels? Perhaps you’re a school that would love to follow in the footsteps of Brentside Academy?

If this Great Big Green Week (or any week!) you’d like to explore changing the way you generate and consume your energy, we’d love to help.

Just get in touch with us here and let’s create a green future together.

Get involved



Joju Solar installed solar on Godalming Leisure Centre

Leisure Centres and Solar – Funding the Future of Community Facilities

Leisure centres are often at the very heart of our communities. They provide a chance for us to focus on fitness and wellbeing and in many cases, leisure centres include a pool. This gives people the opportunity to learn to swim, to get involved in swimming classes, or to make time for a sport that can be both relaxing and invigorating for all ages.

However, if you think about how much energy it takes to operate a leisure centre with a pool, you’re probably right in imagining it doesn’t come cheap.

Counting the cost

Last year, the Local Government Chronicle reported that the Local Government Association and UK Active, (a group committed to getting “more people more active more often”), received “significant anecdotal information” from councils and providers that the energy issue is “driving decisions about facility closures or reduced opening hours”.

A survey of its members revealed the average energy bill was £3.2m in 2022. This represents a 113% increase compared to the £1.5m average cost for each Centre in 2019. 2023 costs are predicted to escalate to at least £3.3m, so what does this mean for the future of these facilities?

Financing the future

Back in the Spring, the Chancellor announced the Swimming Pool Support Fund (SPSF), making £60 million available to support facilities with swimming pools.  The funding was split into two phases. Phase I offered £20 million of revenue for facilities facing increased cost pressures which left them vulnerable to closure or significant service reduction. Monies from this phase have been allocated in full.

The second phase allocates £40 million in capital investment to improve the energy efficiency of public facilities with pools, in the medium to long term. Allocation of these funds will be confirmed by the end of January 2024. Applications closed in late October.

Sport England also made £20m of Lottery funding available to complement the government’s £40m capital fund, increasing the number of facilities benefiting from these improvements. They are administering the fund too.

At Joju, we’ve been helping leisure centres install solar for several years now, to improve energy efficiency and cut operational energy costs. We’ve supported leisure centres all across the UK, including Godalming Leisure Centre, Xcel Leisure Centre and Bridport Leisure Centre .


Working together

If you’ve received, or are about to receive, funding from the Swimming Pool Support Fund and are looking for ways to improve the energy efficiency of your leisure centre building, do let us know. We’re experts at working with public sector organisations and when it comes to the installation of solar on leisure centres, we have the experience to make the whole process hassle free from beginning to end.

As well as design and installation expertise, we understand how important it is for the Centre to remain open, as normal, throughout the project. The way we manage every installation always makes sure this is the case.


S Georges' SPorts Centre, Scott Brown Rigg, Architects

Community funding

If you discover your leisure centre hasn’t been successful in the application for funding, all is not lost. When it comes to improving energy efficiency, cutting costs, and reducing carbon, we’ve been helping community buildings fund solar in a different way for many years. In fact, we helped develop community energy schemes, having installed the very first community-funded installation in Oxford in 2008.

A community energy approach means clean generation is owned by, and benefits, the local community. It’s the way Bridport Leisure Centre’s solar array was funded and at Joju, we’re incredibly experienced and well connected within the community energy sector. There’s no-one better placed to explore the funding of your solar project in this way, meaning you won’t pay a penny. You can read more about our community energy experience and find out more detail about community energy schemes, here.


Joju Solar installation on Bridport Leisure Centre

A bright future?

All in all, when it comes to funding solar energy on leisure centres, the future can certainly be bright! The SPSF will deliver more support for solar to reduce costs through clean, green energy created by the sun.

Community energy could also help to support your plans, if you’re a council or leisure centre who has not had government or Sport England funding awarded to you.

For a chat about how we could help your Leisure Centre work towards a brighter funded future, please do get in touch.

Mike Smyth, Energy4Al, Wey VAlley Solar, Schools Energy Coop, 100 solar installations

A special solar centenary

Here at Joju Solar, one of the things we believe in is the power of community energy, and we’ve worked closely with Mike Smyth for many years to install some pioneering community energy projects for schools (and other similar buildings) across the country.


Mike is the former Chair of Friends of the Earth Trust and the current Chair at Energy 4 All, The Schools Energy Co-operative and Wey Valley Solar Schools Energy Co-operative, and he’s always been passionate about environmental matters.


Last year, we completed our 100th project with Mike, and it was a special one… installing solar panels on the cloisters of Salisbury Cathedral. We couldn’t let this pass without catching up with him to talk about the landmark, Mike’s background and his hopes for community energy in the future.


So, grab yourself a cuppa, take ten minutes and listen to Mike’s story and his feelings about reaching 100… installs, of course!



Find Out More

Solar And Storage LIVE, Contractor of the Year, 2020, Winner, Award

Joju Solar does the Double

Joju Solar has won ‘Contractor of the Year’ at the prestigious Solar & Storage LIVE awards, to add to the ‘EV Charge point Contractor of the Year’ title secured at the EVIEs last month.

The winners were announced on Friday, at the close of a three-day online conference and the awards now put Joju at the top of the pile across all their product offerings – solar PV, battery storage and EV charging infrastructure.

“Winning the Solar & Storage LIVE Contractor of the Year has been a long-held ambition and it feels amazing”, said Joju Solar Co-founder and Technical Director, Dr Chris Jardine.

“We’ve been working in the low carbon technology space for 14 years and this recognition is testament to the hard work put in by our team over that entire period – continually improving both technically and in terms of the service we offer.”

Joju Solar were recognised for their work on helping hundreds of homes reduce their carbon footprint, through solar, storage and EV charging.  Additionally, it has been an intensive year delivering community energy projects.  We installed 2MW of solar PV for Egni Coop in Wales, including the largest solar roof in Wales, at Newport’s Geraint Thomas Velodrome.  This project won the Community Energy Award at the Solar and Storage LIVE awards in its own right.  Other highlights in 2020 include a 39kW community-owned solar PV array on the roof of Salisbury Cathedral.

Joju is also working with more than 80 councils nationwide to install EV charge point infrastructure, simplifying the process and allowing councils to deploy charging infrastructure across their region without spending a penny.

“It’s very pleasing to be recognised across all our product offerings as offering excellent service in what we do.” said Chris.  “But this is still very much the beginning – the climate crisis hasn’t gone away; we still need lots more renewable capacity; and a complete electric transport revolution needs to happen in the next decade.  That’s always been our mission”

Octopus Energy Launch the Tesla Energy Plan


Octopus Energy’s Tesla Energy Plan has now ceased.  It has now been superceded by Octopus Flux.  Octopus Flux is an innovative electricity tariff that changes import and export tariffs throughout the day.  You can top up your battery with cheap electricity in the middle of the night, and earn money by discharging your battery to the grid at peak times.  Read our guide to Octopus Flux here.


Egni Coop, Awel Amen Tawe, Newport, solar, schools

How to install solar in schools

We’re currently building a 2MW community energy scheme with a Welsh community energy group called Awel Amen Tawe.  Their Egni Coop is working with Newport Council to install solar on their schools and other public buildings such as the velodrome.  Dan McCallum from Egni Coop, has written this rather excellent blog piece, looking at the finer details of the project panning and installation process.


Autum, acer leaves, japan

Solar Energy and the Seasons

As a solar engineer, it’s my job to understand the movement of the sun across the sky throughout the year.  However, a technical understanding of solar movement often feels at odds with my appreciation of the world around me.  That confusion comes from our cultural perceptions of the seasons, and their definitions.  So, when exactly do spring, summer, autumn and winter start and end?

Solar Seasons

From a solar perspective, we can look at the movement of the sun across the sky.  We know that at the summer solstice, June 21st , that the sun reaches it’s highest point in the sky, and that our days are longest.  Similarly, at the winter solstice (December 21st), the midday sun is at its lowest point in the sky, and the days are at their shortest.

Midway between the two solstices lie the spring (20th March) and autumn (22nd September) equinoxes.  These dates don’t get as much attention as the solstices, but consider this – on the date of the equinoxes, everywhere on the planet receives exactly 12 hours of daylight.  It doesn’t matter if you’re in Aberdeen or Abu Dhabi, on these days, everyone is equal.

soalr energy, seasonal variation

Solar energy varies from solstice to solstice

These definitions imply that the solstices and equinoxes are the midpoints of the seasons.  It’s always annoyed me when people talk about the summer solstice as the first day of summer – from a solar energy perspective it’s the middle of summer!  Crazy fools!

It’s something our pagan ancestors understood very well.  We know that they understood the passage of the sun across the sky in intricate detail – look how Stonehenge aligns with the summer solstice, and the entrance passageway to Newgrange in Ireland aligns with the winter solstice. The four points between the equinoxes and solstices were marked with festivals, each denoting the beginning of a season.  Beltane (May 1st) marked the start of summer, and Samhain (31st October) the start of winter.  These two, in particular live on in modern times.  May 1st is still celebrated as the start of summer.  In Oxford, for example, 1000’s of revellers gather at dawn to mark the start of summer, with choir singing, morris dancers, bands, and (lets be frank here) the chance to go to the pub at 6am.  Simialrly, Samhain marked the start of winter, and now lives on as Halloween.

Similarly, the start of spring was celebrated on 1st Februray (Imbolc) and the start of autumn (Lughnasadh, or Lammas) on the 1st of August.

And this is where the whole thing falls apart for me.  Really?  Autumn starts on the 1st August?   A week ago we had the hottest day the UK has ever seen, and today it’s meant to be the start of autumn?  Are you kidding me?

Thermal Seasons

The above description of the seasons doesn’t even tally with what we were taught at school.  Back then, I was told:

  • Winter – December, January, February
  • Spring – March, April, May
  • Summer – June, July, August
  • Autumn – September, October, November

So what’s the difference?  It comes about because our perception of the seasons is more about heat than light.  There is a lag between the times of maximum sunlight and the times of maximum heat, as it takes time for the land and oceans to warm up.  This means what we feel (temperature) is out of phase with what we see (sunlight).  If we consider the lag between sunlight and heat to be 1 month, that shifts the solar definition of the seasons in line with what we were taught at school.  If we consider the time lag to be longer at 6.5 weeks, then the crazy fools who say the summer solstice is the start of summer, would actually be correct.

temperature, Seasonal, London

Temperature in London, UK peaks after the summer solstice (from

What if there aren’t 4 seasons?

Now here’s a thought.  What if there aren’t 4 seasons throughout the year?  In north European climates, the year can actually be divided into 6 seasons of 2 months each.  These are based on ecology – the observed plant and animal behaviours that are seen exclusively in these seasons.  They are defined as:

  • Hibernal (winter) – December and January. Bare trees, freezing cold, and snow.  Stay inside, hot chocolate, .mulled wine and Christmas
  • Prevernal (pre-spring) – February and March. Trees begin to bud, that first bright, clear, cold morning of the year, daffodils.
  • Vernal (spring) – April and May.  Trees come into leaf, cherry blossoms, and planting crops in the veggie patch.
  • Estival (summer): June and July. Hot, hot, hot.  Vegetation in abundance, t-shirts, shorts and flip-flops, and Glastonbury.
  • Serotinal (harvest) – August and September. Leaves begin to turn, crops mature (serotinal literally means ripening). The weather is still warm, barbeques in the back garden, but you might need some candlelight at the end of the evening.
  • Autumnal (autumn) – October and November. Leaves turn colour fully and fall to the ground.  Winter coat comes out, hats and scarves, kicking piles of leaves, and catching your breath on the morning air.

seasons, solar, thermal, prevernal, vernal, Estival, Serotinal, autumnal, hibernal

For me, this seems a much better description of the passing of the year.  The ‘extra’ seasons of pre-spring and harvest capture those time of year perfectly, autumn is reserved for just the period of falling leaves, and brilliantly, winter is only 2 months long.

So, as I write this on 1st August, welcome to the start of Serotinal!   That sounds a bit of a clunky phrase – and it might take a while to catch on!  But it doesn’t sound as weird as autumn starting, when its 25 degrees outside.

So, take a look around, observe your surroundings, and find which one of these three seasonal definitions suits you best.

Further reading