Solar Thermodynamic Panels: Independent Test Challenge

Heat meter for the testing of low carbon heating systemsHeat meter on an air source heat pump system at our training centre

UPDATE: We now have a system being tested in our Thermal Testing Laboratory. More information can be found in the links below.

Solar Thermodynamic Panels

There has been a great deal of talk in the energy industry over the past year on solar thermodynamic panels. Some marketing material and testimonials suggest very promising results, however it seems there is has been no independent testing or verification of these systems in the UK.

As an independent test centre, associated with the National Renewable Energy Centre, we are offering free testing for a solar thermodynamic manufacturer who will supply and install a system for free at our headquarters in Northumberland

Solar collector technology

Marketing literature often compares thermodynamic panels with conventional solar thermal systems, but there are key differences in collector design.

Solar thermal collectors have evolved over the last 30 or so years into mainstream construction products with EN and BS standards. Collectors are usually glazed and combine selective coatings and high insulation levels to maximise the flow temperature and optimise solar energy collection efficiency. In the temperature band for heating water (e.g. 20-50 K above ambient) test results show efficiency is typically 55 to 65% for glazed collectors. Unglazed collectors are rarely, if ever, used for heating domestic hot water in the UK because the efficiency falls quite dramatically with increasing temperature difference; although they are very effective for low temperature applications such as heating swimming pools in summer.

The technology is well proven and typically saves between 50 and 70% of water heating energy; a 4m2 system will typically deliver around 1600 kWh of heat at the tank, using about 45kWh of electricity in the process. Back up heat is usually provided by gas boiler.

Thermodynamic panels are usually unglazed flat plates and use refrigeration technology to boost the flow temperature to the heat the water. It can be thought of as air source heat pump (without the fan) that can take additional gains by collecting solar energy if it is suitably orientated. Thermodynamic panels have the advantage they can produce heat from non-optimal collector orientations, or even at night, because of the temperature uplift the heat pump compression cycle offers. The key question is, how efficient is this process and what carbon saving benefit is there over the existing water heating system bearing in mind the current UK grid electricity carbon content?

COP (coefficient of performance)

Thermodynamic systems use electricity for the heat pump compressor and circulation pump. Therefore, like any other type of heat pump, they will have a COP (coefficient of performance), which is a comparison of the energy taken to run, against the output heat energy from the system.

The COP of air-source heat pumps typically lies in the range of 2 to 4, depending on the weather conditions and season. Lower values are usually associated with domestic hot water production because of the high temperature uplift required; the higher values for spring/autumn space heating. Many heat pump suppliers recommend a hot water set point of 48 to 50°C to improve performance, with a regular pasteurisation cycle to safeguard against legionella (often using an immersion heater to 60°C once a week or fortnight).

EN standard heat pump testing requires COP testing at several temperature conditions and when interpreting these results it is important to compare the same conditions; e.g. A7W35 means water temperature of 35° and ambient of 7°C, for which one manufacturer quotes a COP of 4.13, falling to 2.80 at A-3/35 when the ambient is -3°C. This shows the COPs that can be achieved with a suitably designed low temperature heating system, such as underfloor in-slab. However, heating domestic hot water to 50°C requires a much higher temperature gradient, so it is reasonable to assume the COP will fall.

Some Thermodynamic suppliers suggests the COP lies in the range of 2 to 7 – the question is for UK water heating which end of the range is most realistic?


Thermodynamic panels have been temporarily suspended from the MCS installation database. This doesn’t mean the systems cannot be installed in the UK, but that they will not qualify for any financial incentives etc. which are for MCS approved technologies only.

The reasons given by Gemserv, who run the MCS scheme are:

  • The performance of the products being installed in the UK cannot be fully determined; this is mainly due to the fact that these solar systems are being installed using refrigerant but the 12975 testing and certification through Solar Keymark did not use refrigerant as the heat transfer medium.
  • Systems with a compression heat exchange unit are unable to meet the requirements for completing the SAP and performance estimation calculations required under MCS, for example hybrid type systems are not covered fully within the SAP methodology which is required to be completed under MCS.
  • It is not clear how compliance with Part G of the building regulations is fully met, due to the system’s packaged control strategy. Installers are required to meet all parts of the building regulations under MCS, and it is uncertain if installers are able to do this with the system’s packaged control strategy.
  • It needs to be determined if the classification of these systems within MCS are actually Solar Thermal systems or if they should be classified as Heat Pump systems.

Independent test offer

We are willing to carry out an independent test on a single thermodynamic panel system, if provided with one fully installed with all required fittings at our test facility in Northumberland, free of charge by a manufacturer. Due to current high levels of work, we should be able to start the test after the end of May.

We are an organisation completely independent of manufacturers, and part of the National Renewable Energy Centre group of companies, so will give completely honest and realistic results. Whatever the results, positive or negative, we will release them on our website and to our press contacts. Let’s find out how it compares.

If you feel up to this challenge, please get in touch on

Renewable Energy Training Q2 2013 Calendar Published

We have launched the training schedule for our range of bespoke and accredited renewable energy training courses for April, May and June 2013. This includes our two new, highly popular courses.

New Courses for 2013

G59/2 Connecting Large Scale Embedded Generators: This course is aimed at renewable installers, to give them an understanding of the requirements for connecting large scale renewable generators, and the reasons why these exist. We have received extremely good reviews from the first attendees on these courses. From our first four runs of the course, which trained a total of 20 individuals, we found 94% of attendees found the course useful, which 28% strongly agreeing.

Biomass Awareness : The biomass course is aimed at an introductory level, covering a wide range of issues for domestic and commercial scale biomass heating. This includes case studies, details on the fuel sources, and the building regulations. The Renewable Heat Incentive with regard to biomass is also discussed

Financial Incentives

We are running seminars on both the Green Deal and Renewable Heat Incentive, which provide updates with all the latest changes to these two schemes.

LOGIC Accredited Installer Training

We continue to offer LOGIC accredited installer training for photovoltaic, solar thermal and heat pump systems. These courses are essential for installers to fulfill their MCS requirements.


If your company is a North East England based SME, you could receive 100% funding for course attendance. If you are interested in this, please contact Andrew Tipping at

More Information

The renewable energy training schedule can be downloaded here: Narec DE Training Course and Seminar Dates 2013 – apr may jun

Or courses can be booked online here: Renewable Energy Training Calendar

The full prospectus can be downloaded from: Narec DE Training Seminar and Workshop prospectus 2013

If you wish to go on a course which is not scheduled in the calendar, please contact us on, we can also carry out our training courses on customer’s premises where possible.

Does renewable energy cause fuel poverty?

There has been a great deal in the news over the past 12 months over how renewable energy subsidies are increasing the prices of energy, and how they are increasing fuel poverty. But how true is this? What real effect does renewable energy have on bills?

It is true that bills are increasing, and that this is having an impact on fuel poverty levels. A detailed breakdown of cost increases is given in the report “Household energy bills – impacts of meeting carbon budgets” by the UK Government’s Committee on Climate Change, the bill increases were split up as follows (excluding profit margins) from 2004 to 2010 for an average dual fuel bill (electricity and gas) [1].

energy price increases in the UK - keyenergy price increases in the UK - wholesale gas = 64%, transmission & distribution = 15%,  VAT = 4%,  renewable energy = 7%, energy efficiency = 10%

Figure 1: UK dual fuel price increases 2004-2010 – notice the wholesale costs of fossil fuels dominate the price rises [1]

So, we now know the different factors that caused the bill increases. But, excluding profit, how are electricity and gas bills split up? Currently,  bills are set out as follows:

Electricity Gas
Wholesale Fossil Fuel Costs
59% 65%
Transmission, distribution and metering 22% 26%
Renewables/energy efficiency/carbon price 14% 4%
VAT 5% 5%
Table 2: Fuel cost makeup in the UK [1]

It is important to stress that money funding low carbon measures, such as Carbon Emissions Reduction Target (CERT), was used to insulate homes, and thus although the low carbon measures have slightly increased bills, this money is being used to lift the most vulnerable out of fuel poverty.

From the graph above, it can be seen that renewable energy is not increasing bills. The reliance on wholesale prices of gas are a major contributor, and it seems likely that fuel bills will continue to increase with the wholesale price of fossil fuels, which are showing a general long term increasing trend.

The Future

It is important to state that a greater dependence on renewable energy will protect the UK somewhat from these increases, the UK expects to have 30% of electricity from renewables by 2020 [2] . The gas grid will be mainly natural gas, unless there is a considerable increase in the production of gas through methods such as anaerobic digestion. Currently this is limited to a few brewery waste and sewage schemes, so there is considerable growth potential.

Work by the Committee on Climate Change has shown that if renewable energy systems continue to be invested in, this will increase energy bills by £100 by the year 2020. However, not investing in renewable energy could lead to far higher bills. For example,  if fossil fuel gas is the main component of the energy system in the UK in the future, then bills could increase by £600 by the year 2050 [3].

In short, renewable energy is not the major cause of energy price increases, and not supporting renewable energy will cause bills to be increased even more.

[1] – Household energy bills – impacts on meeting carbon budgets, Committee on Climate Change, 2011

[2] – National Renewable Energy Action Plan for the United Kingdom“, UK Government, 2009

[3] – Energy prices and bills – impacts of meeting carbon budgets“, Committee on Climate Change, 2012

The effects of fuel poverty on children

Narec Distributed Energy have been carrying out a range of work to use renewable energy and low carbon technologies to fight poverty, specifically fuel poverty, but this also has a major impact on child poverty.

Fuel poverty can have major effects on children. To give general information on child poverty in the UK, a well referenced selection of information is given by CPAG (Child Poverty Action Group) [1]:

  • There are 3.8 million children living in poverty in the UK today. That’s 29 per cent of children, or more than one in four. [2]
  • There are even more serious concentrations of child poverty at a local level: in 100 local wards, for example, between 50 and 70 per cent of children are growing up in poverty [3].
  • Work does not provide a guaranteed route out of poverty in the UK. Almost two-thirds (58 per cent) of children growing up in poverty live in a household where at least one member works [2].
  • People are poor for many reasons. But explanations which put poverty down to drug and alcohol dependency, family breakdown, poor parenting, or a culture of worklessness are not supported by the facts[*].
  • Child poverty blights childhoods. Growing up in poverty means being cold, going hungry, and not being able to join in activities with friends. For example, 71 per cent of families in the bottom income quintile would like, but cannot afford, to take their children on holiday for one week a year [2].
  • Child poverty has long-lasting effects. By 16, children receiving free school meals achieve 1.7 grades lower at GCSE than their wealthier peers [4]. Leaving school with fewer qualifications translates into lower earnings over the course of a working life.
  • Poverty is also related to more complicated health histories over the course of a lifetime, again influencing earnings as well as the overall quality – and indeed length – of life. Professionals live, on average, eight years longer than unskilled workers [5].
  • Child poverty imposes costs on broader society – estimated to be at least £25 billion a year [6]. Governments forgo prospective revenues as well as commit themselves to providing services in the future if they fail to address child poverty in the here and now.
  • Child poverty reduced dramatically between 1998/9-2010/11 when 900,000 children were lifted out of poverty [2]. This reduction is credited in large part to measures that increased the levels of lone parents working, as well as real and often significant increases in the level of benefits paid to families with children.
  • Under current government policies, child poverty is projected to rise from 2012/13 with an expected 300,000 more children living in poverty by 2015/16 [7]. This upward trend is expected to continue with 4.2 million children projected to be living in poverty by 2020.

According to the charity Shelter in the report [8]; “These children are living in damp, cold, infested housing or on estates that are shamefully neglected and ridden with fear and filth. Living at the whim of bad landlords who threaten and neglect. Living under the cloud of eviction and debt. Or they are literally homeless – not on the streets but in emergency housing waiting for somewhere permanent to live.”

Information is given by “The Impact of Fuel Poverty on Children” policy briefing written by Professor Christine Liddell [9]. This looked into peer reviewed research globally on the effects of fuel poverty on children.

For example, a study in the US compared two groups of low income children in five different cities. Group 1 lived in families which were receiving a winter fuel subsidy, and group 2 were not. It was found that infants in homes without subsidy were 40% more likely to be admitted to hospital or primary care clinics in their first three years. They were also more likely to be underweight.

Why is this? Like anyone, infants stay warm by burning calories. Thus when they are cold, they have fewer calories available for other jobs such as growing or building a healthy immune system. Additionally, the paediatricians involved in this work speculated that there are risks to children’s cognitive development from years of being underweight.

To put it simply, as stated by the housing charity Shelter, “bad housing wrecks lives”

Work carried out by Narec Distributed Energy which has impacted on fuel poverty includes:

The most recent Narec news stories on this work are:

[*] For example, G Hay and L Bauld, Population estimates of problematic drug users in England who access DWP benefits, Department for Work and Pensions, 2008, suggest that 6.6 per cent of the total number of benefit claimants in England were problem drug users. While drug misuse may prove to be a key reason this group of people finds it hard to escape poverty, it clearly has no explanatory power for the other 93.4 per cent of claimants.

[1] “Child poverty facts and figures,” [Online]. Available: [Accessed 2012 08 30].
[2] “Households Below Average Income, An analysis of the income distribution 1994/95 – 2010/11,” Department for Work and Pensions, 2012.
[3] “Child Poverty Map of the UK,” End Child Poverty, 2011.
[4] “GCSE and Equivalent Attainment by Pupil Characteristics in England 2009/10,” Department for Education , 2011.
[5] “Life expectancy at birth and at the age of 65 by local areas in the UK, 2004-6 and 2008-10,” Office of National Statistics, 2011.
[6] D. Hirsch, “Estimating the costs of child poverty,” Joseph Rowntree Foundation, 2008.
[7] J. B. a. R. J. M Brewer, “Child and working age poverty from 2010 to 2020,” Institute for Fiscal Studies, 2011.
[8] “Toying with their future – the hidden cost of the housing crises,” Shelter, 2011.
[9] C. Liddell, “The impact of fuel poverty on children,” Save the Children, 2008.

Construction of 3.4MW wind turbine in Blyth

Blades for 3.5MW wind turbineBlades for 3.5MW wind turbine

Over the past week we have been watching the construction of a new REPower 3.4MW wind turbine for Hainsworth Energy.

It has been an incredibly impressive event to watch, as after two weeks of preparation the whole system was put together in four days.

The system will be commissioned at the end of September.

Device Statistics

  • Power Output: 3.4MW
  • Energy: Enough to supply over 2000 homes a year
  • Height: 128 meters

Projects such as these help protect the UK from the global energy prices and help combat anthropogenic climate change.

Below we have a range of photos, and more on the Narec Distributed Energy Twitter


Construction of RE Power wind turbine in BlythPart one of the tower put in place
Construction of RE Power wind turbine in BlythPart three of the tower lifted
Construction of RE Power wind turbine in BlythCrane ready to move part three of the tower into place
Construction of RE Power wind turbine in BlythFirst three parts of the tower connected
Construction of RE Power wind turbine in BlythNacelle lifted up toward the top of the tower
Construction of RE Power wind turbine in BlythNacelle moved into place
Construction of RE Power wind turbine in BlythNacelle now connected
Construction of RE Power wind turbine in BlythClose up of nacelle
Construction of RE Power wind turbine in BlythThree blades connected to hub lifted as one
Construction of RE Power wind turbine in BlythBlades moved into position
Construction of RE Power wind turbine in BlythCareful lifting an alignment of blades
Construction of RE Power wind turbine in BlythCompleted wind turbine

Narec Distributed Energy launch new renewable energy website

sunflowersNarec Distributed Energy

At Narec Distributed Energy we have now launched our own website.

We are part of the UK’s National Renewable Energy Centre, a world leading centre for all renewable and low carbon technologies. This website is dedicated to the substantial work which Narec Distributed Energy carry out in renewable and low carbon technologies, particularly in the built environment.

We carry out a range of services on a range of different renewable and low carbon technologies, using our dedicated team within Narec Distributed Energy, and also using staff from the wider National Renewable Energy Centre.

To see a selection of the project we have work on (or are currently working on) please have a look at the case study section of this website:

To see the latest news from Narec Distributed Energy, please subscribe to the RSS for our news section, and to our twitter at @NarecDE

We thank 21Inspired for the quick and professional website which they created