Capable of offsetting typically around 30% of the energy demands for water heating, solar thermal systems are ideal for organisations that rely on large amounts of domestic hot water (DHW).

For the existing buildings, 80% of which are still expected to be in use by 2050, the application of solar thermal pre-heat is a well-established means of reducing demands on prevalent gas-fired water heating helping to offset operational costs but actively cutting carbon emissions from the buildings. Commercial new builds or refurbishments, however, are either mandated or opting to shift to direct electricity are finding that move comes with a new financial burden as electricity remains substantially more expensive to operate than gas – currently by a factor of 3.8. Undisputed carbon and cost savings mean we are seeing a definite upswing in interest for new solar thermal systems with a ten-year return on investment being very achievable.

A correctly designed and sized system will consider the daily usage and peak demands. Its aim is to serve all peaks from storage, with the size of the peak determining the size of pre-heat. The recovery time for peaks is what ultimately determines the number of solar collectors a building requires. The design process also sizes usage with available space. A south-facing and unobstructed roof with an inclination of 30° from the horizontal is optimal, though by no means essential as modern solar collectors can be installed in a variety of permutations. Unsurprisingly, solar thermal collectors do suffer if the building is significantly shaded, in which case a commercial air source heat pump may be a preferred option to produce low-carbon heat.

Modular, high-performance flat plate collectors can be situated on or integrated into flat or sloped roofs, as well as mounted on a building’s façade. By far the most efficient way to heat water with solar energy, flat plate collectors offer a smaller footprint compared to equivalent solar photovoltaics (PV) for DHW. A typical 4 kW PV system requires approximately 16 panels covering 25m² of roof to match just three flat plate collectors covering just 6.6m² roof area. This makes solar thermal a prime choice when roof or facade space is limited.

Adveco collectors feature a copper meander absorber through which passes the solar fluid (glycol). The fluid transfers solar energy as heat to the system’s water via an indirect cylinder. To correctly manage solar fluid drain back technology should be applied to protect the fluid from overheating. This can ‘cook’ the fluid to a tar-like consistency causing permanent damage to the collector. As the name implies the solar fluid drains from the collector to a reservoir when not in use. Flat plate collectors with an integrated drain back module offer a more cost-effective (as there is no requirement for large solar storage) and more efficient (as there is no call to dump unused heat) approach. The technology has proven itself in the field with fluid changes required perhaps once in eight years, rather than the expected three.

For new build properties with electrical connection, the gas water heater is replaced with an electric boiler and cylinder to supply the afterheat which raises system temperatures to a necessary 60°C. This hybrid approach maximises the solar thermal input, typically offsetting 30% of the electrical demand, although it could be more depending on location. Adveco has simplified this hybrid approach by integrating a packaged FUSION E electric water heating system. This also gives the option of adding an electric immersion to the system as a backup for enhanced resiliency when assured water heating is a business-critical service. The all-electric solar thermal approach further reduces carbon associated with grid electric systems and aids in lowering operating costs.

This hybrid approach can be further extended with the inclusion of air source heat pumps to provide the initial pre-heat for the system. Operating at lower temperatures with the cold feed maximises the efficiency of the heat pump, reducing electrical operating costs and raising working flow temperatures from 10°C to 40°C. This is not hot enough for commercial applications, so the pre-heated water is then passed to the mid-solar thermal system. Essentially free to operate, the solar thermal system boosts the working flow temperatures from 40°C to at least 50°C. Although not operating at maximum potential, there is enough advantage gained from solar thermal to warrant the additional system complexity and capital investment. During summer months it is possible for the solar thermal system to deliver the necessary 60°C working flow for safe provision of commercial hot water. But to ensure safe, consistent, and necessary high operational temperatures, the water is passed to the FUSION electric water heater. Here final consistent water temperatures of up to 65°C are assured year round.

To date, Adveco has designed and supports more than 800 live solar thermal systems across the UK and such hybrid approaches are unavoidable if commercial projects seek a sensible, practical, and cost-effective path to low-carbon hot water.



The National Infrastructure Commission for Wales (NICW) has recommended ways to maximise renewable energy generation and help the country meet carbon targets.

The NICW called for an “immediate review” into building regulations that would see all new housing developments fitted with solar panels and batteries to store excess energy.

The extremely low cost of both solar thermal and photovoltaic technologies is one of the reasons the NICW suggests mandating them on newbuilds.

According to the International Energy Agency, the cost of solar has plummeted in recent years because of improvements in panel technology. This has led to a higher percentage of sunlight being converted into electricity. In the early 1980s, the average cost of solar panels was around £24 per watt. Today, it is less than £0.40 per watt – a 98 per cent cost reduction.

The NICW said that solar thermal technologies in particular can make a sizeable impact on buildings with high demand for hot water, such as leisure centres, swimming pools and care homes.

It also said it had received evidence that housing developers were “banking” projects that were not advanced in the development process so they did not need to comply with modern energy efficiency requirements.

To avoid this, “any potential loophole in the transitional arrangements must be closed to ensure that the new developments comply with the highest standards”, it said.

It suggested introducing a sunset clause that would apply the latest energy efficiency requirements to projects that have not been developed in a “timely” fashion.

The NICW also called on the Welsh government to present a plan for Welsh energy leading up to 2050 and revamping the energy grid.

Dr Jenifer Baxter, deputy chair of the Commission, said:

“We are now facing a time in our history where if we do not make a concerted effort to change how we deliver new infrastructure then our ambitions for net zero and the wellbeing of future generations will be in jeopardy.”

Aleena Khan, NICW commissioner, said:

“As a young person, I understand the importance of Wales acting decisively in tackling the climate and nature emergencies. I hope the Welsh government will consider each of our proposals carefully and the impact they will make on us meeting our energy and carbon targets.”

Source: Engineerin & Technology

Don’t delay: Leading solar manufacturer urges installers to take up PV training as demand surges


A leading solar photovoltaics (PV) and energy storage solutions manufacturer is calling on both non-PV installers and existing solar contractors to invest in training, with interest in solar predicted to soar as a result of the as the Energy Price Guarantee (EPG) increase.

Although the current EPG has been announced to stay at £2,500 for a further three months before increasing to £3,000 in July, solar is already seeing unprecedented levels of interest from homeowners and landlords. One energy firm, Good Energy, found that solar installations doubled to over 130,000 in 2022.

Now, GoodWe is urging tradespeople to start skilling up in solar today to take meet this growing demand and is launching a series of training sessions to help tradespeople add PV to their services.

The free-to-attend training sessions are part of the company’s GoodWe PLUS+ Installer Programme. Hosted online by a GoodWe technical specialist, the series is run in three separate parts, and is designed to help installers from design and installation, through to commissioning and aftermarket servicing. The programme consists of the following modules:


  1. Portfolio and Application – 9th May 2023.
  2. Commissioning and Monitoring – 11th May 2023
  3. Troubleshooting and Service – 16th May 2023


Eugene Lucarelli, Marketing Manager for GoodWe UK, said:

“Over the past year, we have seen the solar industry skyrocket. Rising energy prices have pushed people to look at futureproofing their energy supply and protect themselves from volatile, expensive grid costs.

“It represents a great opportunity for tradespeople like electricians and roofers, who may already have a slight connection with solar, to really step into the industry and add PV to their portfolio. We’re here to enable this through our easy-to-access training seminars in May, hosted by one of our leading technical representatives.

“The webinars themselves help break down everything an installer would need to know about solar solutions. It’s also a great refresher course for existing solar installers, and by going through the training sessions, you can become an accredited GoodWe PLUS+ installer and unlock other benefits from us too, including additional warranty on our residential inverters.”


As well as training installers on the core elements of a solar system solution – inverters and batteries – delegates can also learn about complementary products, such as EV chargers. These products are becoming increasingly popular and are a requisite for certain new builds under Part S of the Building Regulations – Infrastructure for the charging of electric vehicles.

Accredited GoodWe PLUS+ installers will benefit from an extended ten-year warranty on GoodWe’s range of string inverters for residential applications. Once training has been completed, all installers need to do is register for an installer code for GoodWe’s monitoring solution, SEMS, install an inverter and then connect the inverter to SEMS.


For more about the GoodWe PLUS+ programme and to sign up to the training, please visit

ABU DHABI, UAE, Jan. 18, 2022:  Sungrow, the global leading inverter solution supplier for renewables, officially launches the brand-new central inverter — “1+X” Modular Inverter at World Future Energy Summit, a high-profile international event for global sustainability and transition to clean energy. “1+X” Modular Inverter is the most innovative central inverter solution which Sungrow is promoting worldwide and it is expected to lead the next generation central inverter designation for large-scale utility solar plants.

As the World Future Energy Summit is in full swing at Abu Dhabi, global innovators, experts, entrepreneurs and investors meet, exchange, network and trade there. As a significant participant for the Solar& Clean Energy Expo, Sungrow showcases its industry-leading solutions for residential, commercial & industrial, and utility solar and ESS application, demonstrates technological breakthroughs and innovations, and thereby, incubates business chances with potential investors. On this grand stage for global cleantech, “1+X” Modular Inverter is definitely one of the game-changing stars that shape the future energy.

The cutting-edge technologies of this product center one key word — “Modularization”. “1+X” inverter solution boasts modularization at the inverter level, the system level and the component level. Three-level modularization makes power plant design more flexible and post O&M more convenient in the future.

Firstly, “1+X” modular inverter features 1.1MW single unit as the minimum, but the block capacity can be expanded to a max. 8.8 MW by combining 8 units just like building blocks. Customers can choose from 1.1MW to 8.8 MW to meet their best demands. Secondly, the system modularization makes PV module configuration more flexible to extend. The inverter supports maximum 2 times DC/AC ratio. 1+X modular inverter has 42% more MPPT than the traditional central inverters, and it realizes the string-level management by new wireless DC combiner. Increased MPPT and more refined management lead to higher electricity generation. The DC/ESS interface built in this solution also supports connecting to energy storage system, enabling customers to enjoy the storage function for future energy usage. Thirdly, the component modularization realizes the plug and play function, reducing the maintenance from 6h to 2h. Moreover, since each inverter also works in individual unit, it can be directly replaced by onsite backup inverter if failure occurred. Hence, the three-level modularization, once again, sets this gigantic product apart from others.

Sungrow’s “1+X” Modular Inverter has soon received great popularity since its debut in Chinese domestic market in March, 2021. By far, Sungrow achieved more than 500MW order of this product and they are supplying various solar plants around China. After its release to international market, “1+X” Modular Inverter will start its clean-power journey across the world and meet the future energy demands with its outstanding flexibility, convenience, and simplicity.

The UK’s first energy positive office, the Active Office, was opened in June last year at Swansea University. Designed by SPECIFIC Innovation and Knowledge Centre to be powered entirely by solar energy, the Active Office aims to generate more energy than it consumes over the course of a year.

The Active Office isn’t just meant to be a high performance building for its own sake, but also to demonstrate how well buildings can perform with technology available today. The building is packed full of cutting edge, commercially available technology to help generate, store and manage energy for the building.

One piece of technology provides both electricity and heat to the building; the photovoltaic thermal (PV-T) system by Naked Energy. Made up of a number of photovoltaic panels contained in vacuum sealed tubes, the system has been mounted onto the front elevation of the building and could potentially provide heat energy for the entire building through spring, summer and autumn.

More solar energy is collected through the roof which is covered in, or more accurately made up of, solar cells. The PV cells are bonded directly onto pre-painted steel to create a roofing system that can be installed using conventional methods. The Active Office features the first commercial installation of BIPVco’s technology on a curved profile, which aside from adding architectural flair, will also generate power throughout the year even in low light conditions.

The various systems are monitored by extensive metering installed throughout the building, enabling SPECIFIC to determine where energy is being generated and consumed. This is reflected in a real time display in the entrance foyer, allowing occupants and visitors to find out how the building is performing.

However, the building can’t reach its energy positive target if all the energy it generates is wasted. “We took a fabric-first approach to reducing energy consumption,” commented Joanna Clark, Building Integration Manager with SPECIFIC and Architect for the Active Office. 

The Active Office was designed and conceived by SPECIFIC Innovation and Knowledge Centre and funded by Innovate UK with support from Swansea University and the European Regional Development Fund through the Welsh Government.

It was manufactured offsite by Wernick Buildings, in their factory in nearby Port Talbot. SPECIFIC knew that modular construction could deliver the levels of performance they needed against a challenging programme and budget.

Months later, the choice of modular is being borne out by data. On current performance, SPECIFIC predict an annual consumption of approximately 20MWh versus an annual generation of 24MWh.

The future looks bright for this new type of solar-powered building design. In September, the Chancellor of the Exchequer Philip Hammond announced funding for the Active Building Centre through the Industrial Strategy Challenge Fund and UKRI. The new independent national centre will seek to remove barriers and accelerate market adoption of new Active Buildings. 

It seems likely that modular construction will play an important part in progress towards a low carbon future. 

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