Category: Sustainability

In December 2019, ThamesWey commenced a new trial of utilising battery storage, where a centralised battery system was set up to capture spare renewable electricity generation from the rooftops of group of properties, to reduce reliance on the national grid and decrease the greenhouse gas emissions for the properties. Joju Solar installed three Tesla Powerwall batteries which have the ability to store 40.5 kWh of unused solar power generated during sunlight hours, and supply this back to the properties whenever they need it, even when the sun is not shining.

The centralised battery system provides a more effective way for the excess solar generated electricity to be utilised on a very localised scale. The benefit of a community system over individual battery units is that the properties have shared access to the stored energy, to use when it is really needed, no matter how much direct solar energy they have used. This evens out the natural variations in the way each household uses energy from differing lifestyles and means that less excess energy goes to waste and overall less grid energy is used. Read more about the system setup here.

ThamesWey has looked back at the data from the last 2 years to understand how the system has performed and the results are a testament to the effectiveness of this type of system. The monitoring shows that the use of grid electricity at ‘peak-times’, when national grid supplied electricity is typically generated from the most carbon intensive sources, has reduced significantly. Before installation, 11.5% of grid supplied electricity was needed during these peak times. During the first year of battery operation (2020), this reduced to 3.4%, but in the second year (2021) this figure reduced even further to just 0.5%, almost eliminating peak time grid electricity consumption altogether. The table below shows these results.

Even during the winter months when no excess solar power is available, the battery draws energy from the grid overnight and stores it for use in the day. The overnight, off-peak electricity is typically generated from the cleanest energy sources, so both the cost and carbon intensity is much lower. By using this stored grid energy during peak hours, instead of directly using ‘peak time’ grid electricity, the households are reducing their carbon emissions by around a third. The Tesla system intelligently learns how the households typically use their electricity to operate in the most efficient way, the improvement in performance from 2020 to 2021 shows the progress and impact of this learning.

The project has successfully demonstrated how the energy generated from a zero carbon energy source can be maximised whilst also providing a benefit of reducing pressure on the national electricity grid during peak times. This installation forms an important part of ThamesWey’s ongoing commitment to transition to sustainable, zero-carbon energy and is another step towards a carbon neutral future for Woking.

ThamesWey’s longstanding ‘Action Surrey’ project delivers domestic energy efficiency services to the local area on behalf of a partnership of Surrey local authorities. In the last year Action Surrey has been working hard to deliver the ‘Green Jump Surrey’ project, helping Surrey residents access the Green Homes Grant to improve the energy efficiency and environmental performance of their homes.  550 households have benefitted from this project so far, read on for examples of the improvements that have been achieved.

Mr Zaman in Woking had always been deeply interested in installing solar PV, and thanks to the Green Jump Surrey project, finally got his chance. He was appreciative that the Green Jump Surrey application process has been fast, clear and efficient and is pleased to now have 12 solar photovoltaic panels generating free, renewable electricity. The property was also suitable for both loft and cavity wall insulation, which were installed alongside the solar panels, to create a home that feels much warmer as a result.

Mr Halimic in Old Woking benefitted from a similar blend of insulation and renewables to boost the efficiency of his 1950s property. The loft and cavity walls were insulated and the roof is home to a new solar thermal system, which generates renewable hot water, and a 4kW solar PV system to provide renewable electricity. The combined environmental benefits of these measures have improved the Energy Performance Certificate or ‘EPC’ rating of his property from D60 to an above average C71. The property will use around 5,000 kWh less of energy, which equates to a saving of around £600 and 2.7 tonnes of carbon per year. Mr Halimic was grateful that the scheme had supported this level of improvement and that Action Surrey had provided such a friendly, helpful service to make this happen.

In Guildford, Mr Franzoni also benefitted from a fully funded solar PV system through Green Jump Surrey. Action Surrey’s trusted contractors set up a 5kW system with 15 panels on the roof. Mr Franzoni is very proud to be the first on his street to be powering his home using his own source of renewable energy, as well receiving payment for any excess that he exports to the national grid, as part of the Smart Export Guarantee.

Since there is no space between the boundary of his property and the pavement, a complex scaffolding arrangement and permission had to be arranged to access the roof safely. Mr Franzoni also wanted to externally insulate his solid brick walls, as it was difficult and expensive to heat the house to a comfortable level when the heat escaped easily. The close proximity to the pavement meant was a challenge, but Action Surrey’s trusted contractors found a solution that worked for all by insulating the rear wall of the property, which was also funded through Green Jump Surrey. All these improvements raised the home’s energy efficiency rating from a D rating scoring 59 points on the EPC, up to a spectacular 80 points which is a C rating.

The Green Jump Surrey project has enhanced the environmental performance of the homes, and has encouraged the homeowners to consider further improvements. These applicants all expressed no hesitancy in apply for future grants, with aspirations for further insulation, upgrading double glazing and installing an air source heat pump.

ThamesWey’s long-standing home energy efficiency service ‘Action Surrey’ delivered it’s largest home improvement project to date in 2021 – ‘Green Jump Surrey’. Read how one Surrey resident has benefitted from free insulation to reduce their heating bills and carbon dioxide emissions.

Trevor applied to Green Jump Surrey to improve the energy efficiency of his 1920s semi-detached property in Guildford.

His property, like others of this age, was built with solid brick walls which are very energy inefficient and lose heat easily. External wall insulation (EWI) was therefore identified by Action Surrey’s energy advisors as the most effective way of improving the home’s energy efficiency. Trevor was referred to one of Action Surrey’s installation partners who carried out the works on the property completely free of charge.

Here’s what Trevor had to say about the process:

“Overall, I’m really happy with the quality of the work completed at my property. We used to have terrible damp problems here, mould would latch on to freezing cold walls to the extent that furniture needed to be moved well away from wall, so it didn’t collect condensation too. It has only been a month since the insulation has been installed and there has been an instant improvement. The condensation mould has been eliminated in such a short space of time, even though its winter, which is absolutely fantastic.

The house would normally drop down to 15 degrees Celsius by the time we woke up in the morning, but now the temperature barely reduces at all – it’s still 19 degrees after a cold night without the heating on! Although it has not been long enough to see an entire winter’s heating bills, we are expecting a significant reduction in our gas consumption. It has come at a great time with the massive energy price rises we are seeing, so I feel very lucky to have got the insulation when I did. It should also keep my home cooler in summer, which will be a welcome relief during those rare heatwaves. The insulation has a 40-year lifespan so I am looking forward to reducing my heating bills and living in a more comfortable home for a long time to come.

I found the Green Jump Surrey application process very easy too. I could do it all online and even though I am not the best with a computer, it was simple and straightforward. The energy advisors at Action Surrey were always on hand to help if I had any queries and made sure I understood the process. The offer of all this free improvement work, which cost over £13,000, sounded too good to be true, but I am so glad that I did apply as it was exactly as advertised.

Besides the improvements that the external wall insulation has made to my comfort, mould problems, heating bills and carbon footprint, the outside of my home has been completely transformed. The house has gone from one of the most tired looking properties to one of the best looking on the close with a really crisp and neat rendered finish. I also took the opportunity to replace my old cast-iron guttering and ageing facias, so the house really has transformed.

Overall, I would really recommend the Green Jump Surrey project and external wall insulation. Whilst there was some waiting involved and disruption during the installation, it was so worth it to have this fantastic improvement to my home made free of charge, which I will benefit from for decades to come.”