PowerPoint Presentation

Technology OverviewPV-T basicsDavid Browne

Bespoke project assessment

What are Photovoltaic panels3PV cells are made from layers of semi-conducting material, usually silicon. When light shines on the cell it creates an electric field across the layers. The stronger the sunshine, the more electricity is produced. Groups of cells are mounted together in panels or modules that can be mounted on your roof

Can be cheap to installCut your electricity bills: sunlight is free, so once you've paid for the initial installation your electricity costs will be reduced. Get paid for the electricity you generate: the governments Feed-In Tariffs, even if you use it.Sell electricity back to the grid: if your system is producing more electricity than you need, or when you can't use it, you can sell the surplus back to the grid. Cut your carbon footprint: solar electricity is green, renewables energy and doesn't release any harmful carbon dioxide] or other pollutants. A typical home solar PV system could save over a tonne of carbon dioxide per year that's more than 30 tonnes over its lifetime.

What are Solar Thermal panels4Solar water heating systems use free heat from the sun to warm domestic hot water. A conventional boiler or immersion heater can be used to make the water hotter, or to provide hot water when solar energy is unavailable.

Can be cheap to installHot water throughout the year: the system works all year round, though you'll need to heat the water further with a boiler or immersion heater during the winter months.Cut your bills: sunlight is free, so once you've paid for the initial installation your hot water costs will be reduced.Cut your carbon footprint: solar hot water is a green, renewable heating system and can reduce your carbon dioxide emissions.Can take a long time to pay back as the incentives tariff is high but the deeming only gives certain amount of Kwh to be paid on.We tend to install PV-T in place of Solar Thermal panels.

What are Hybrid solar panels (PV-T)5Photovoltaic thermal (PVT) technology refers to the integration of a PV and a conventional solar thermal collector in a single piece of equipment. As a consequence this technology combines a simultaneous conversion of solar radiation into electricity and heat. General Benefits:Up to 15% annual Electric kWh uplift per kW installedGreater total energy generation per m of roof space Greater kg of CO displaced per m of roof area per year than PV or solar thermalPanels that are MCS accredited for both solar thermal and PV can claim the Fit and RHISingle panel type on roof and single installation General Stumbling blocks:Should only be used if there is a requirement for both heat and power.People tend to think in price per electrical watt and compare to PVSome early panels ineffective along with past miss-selling leading to bad pressInstallation Complexity

Types of Hybrid solar panels (PV-T)6PowerVolt 200/630:

This is the Volther PowerVolt Panel

1.37m , 200W Pk(e), 630W Pk(Th)

High Electrical Yield

Low temp application only

Lots of Kwh thermal at low temp

Perfect for pre-heat systems

Great for ground charging

Good as source for heat pump

Types of Hybrid solar panels (PV-T)7PowerTherm 180/680:

This is the Volther PowerTherm panel

1.42 m , 180W (e), 680W (Th)

Similar annual electric yield to PV

Low to mid temp range applications

Lots of Kwh thermal

Great for ground charging

Useful for direct hot water contribution

Great for hitting code in housing developments

8Panasonic HIT technologyHigh Module efficiency (19%)High quality Japanese ModuleGood low light propertiesTakes less roof spaceLess on roof kit/ lower install costMore expensive than standard PV can mean a more expensive installation.

9Panasonic HIT technology

HIT solar cells improve boundary characteristics and reduce power generation losses by forming impurity-free i-type amorphous silicon layers between the crystalline base and p- and n-type amorphous silicon layers.

Solar Thermal Temperature vs. efficiency10

Photovoltaic Temperature vs. efficiency relationship11

Heat Pump Temperature vs. efficiency12

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Photovoltaic Temperature vs. efficiency relationshipSolar Thermal Temperature vs. efficiency relationshipHeat Pump Temperature vs. efficiency relationship

Why do we hybridise renewable technologies?

1. Both solar thermal and PV give a larger volume of energy at a lower temperature2. Heat pumps run more efficiently with a higher source temperature3. Using these relationships, the controller can balance heat flows to increase the efficiency of all parts of the system

14Heat pumps and their applicationsCOP (efficiency) is linked to the amount the heat pump raises the temperature between the source and the targetStandard methods for maximising the COP of a heat pump revolve around low temperature delivery.We increase the source temperature to drop the delta tIntegration with PV-T benefits to Heat pump; higher COP, less compressor workBenefits to the PV-T; increased outputs, longevity

15Hybrid Solar Solution

16Thermal energy storage and solar charging

17BoreholesReliable source of heat when installed properly.Is used without solar charging (can self replenish)Can store heat inter-seasonally when charging the ground as long as not flowing waterWhen charging if spaced close together or in radial fashion can get heat bubbles through interference.Geology can mean they are suitable for a property.Can be unforeseen issues (underground caverns)Can be expensive

18Horizontal loops and Slinkey'sCan be cheaper to installAre used without ground charging (can self replenish)Requires large amount of ground area for installationCannot be used for inter-seasonal storage although can for diurnalSlinkey's reduce the amount of ground works/ land required although still significantMore annual temp fluctuation than borehole

19Water sourceCan be a lot cheaper to installVery project specificOpen / closed loop- maintenance and CAPEXLake loops- body of water size/ usageRiver open source - minimum flow considerations HE maintenanceNo inter-seasonal storageCan still be used as heat dumpPV-T tops up when available (day) through Heat exchanger

20Earth Energy BankNew build solution for low energy housesDoesnt go deep so no geological reports and is not restricted to locations.Build up heat over time from solar input (not self replenishing).Under the house so no requirement for large garden space

Main Design considerations with HSSInverters:sizing of the inverters as higher peak galvanic isolation for inverters used with PV-TControl :With PV-T we do not modulate pump speed as we want Isothermal surface of panelPulsed heatTanks and coils:Powervolt for Pre-heat Right panels for right applicationIf low source temp then the heat pump either requires control of max ground return temp or blending of source side of Heat pump

Advantages through Hybridisation ofrenewable technologies

Highest CO2 displacement per m roof space for solar technologyMultiple revenue streams (FIT and RHI)High energy cost savings Maximize available roof spaceReduced installation cost as opposed to independent technologiesWhen integrated correctly can reduce complexity of systemsKey to development is integration of renewablesSeparates you from the competitionAllows you to specify the right system for the project dependent on individual requirement's

MultisourceWe use standard heat pumps as multisource but with ground and PV-T as the sources.Excess solar heat tops up the Air temp and so improves the COPIn return the heat being dumped keeps the PV-T cooler and maintains a higher electrical conversion efficiency.The electricity from the panels offsets the compressor running of the HP.Low cost - high efficiencyhigh CO2 displacement densityGood returns

Thank YouConvert Energy LtdCanterbury Innovation Centre, Unit 70, University Road, Canterbury, Kent, CT2 7FGMain:+44(0) 2030048338Mail: info@convertenergy.co.uk