LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING RENEWABLE ENERGY TECHNOLOGIES

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING

Level 3 Re-cap Renewable Technologies –Solar Thermal (Solar Water Heating) –Solar PV (Photovoltaic Cells) –Wind Turbines –Biomass & Bio-fuel Boilers –Combined Heat & Power (CHP) –Biomass Combined Heat & Power –Ground Source and Air Source Heat Pumps Information relating to renewable technologies can be found in ADL2A supporting document Low or Zero Carbon Energy Sources Strategic Guide. DCLG

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING Solar Water Heating - Collectors Flat Plate Collectors –Thin copper or aluminium absorber sheet, with black coating, backed by coil of small bore pipework containing fluid, all encased within glass cover –Fluid circulates through pipework and heat is transferred to the fluid from the absorber ‘plate’ Evacuated Tube Collectors –Series of modular glass tubes containing vacuum, mounted in parallel, with absorber plate and thin pipe. –Vacuum provides insulation and is reason for greater efficiency Formed Plastic Collectors –Consist of tubes or formed plastic panels through which water is circulated and heated by the sun’s radiation –Not suitable for year-round use. Only useful when ambient air temperature is greater than fluid temperature –Used primarily for heating of swimming pools in warm climates

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING Examples of Solar Water Systems

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING Solar Water Heating - Collectors Flat Plate Collectors –Pros:Less expensive Slightly more efficient in warmer weather Extremely robust Can be integrated into roof to improve aesthetics –Cons: More difficult to install Once installed difficult to adjust or move Heavy

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING Solar Water Heating - Collectors Evacuated Tube Collectors –Pros: Easier to install Less weight on roof More efficient in cold weather –Cons:More expensive Less efficient in warm weather Cheap systems lose vacuum and therefore efficiency More prone to damage during installation

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING Flat Plate Solar Thermal Collector Evacuated Tube Solar Thermal Collector

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING Solar Water Heating - Systems Compact Systems (Passive) –The simplest systems are passive solar water heaters –Most common in regions without extensive periods of below freezing temperatures –Water circulates without aid of pumps or controls Pumped Systems (Active) –Use pumps to circulate water (or antifreeze solution) through collectors Direct Systems –“Open Loop” system –Water heated within system is used directly by the building occupants –Susceptible to freezing as antifreeze solution cannot be used Indirect Systems –“Closed Loop” system –Heat transferred from glycol solution by way of heat exchanger

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING Typical Passive System

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING

Solar Water Heating – Drain Back When there is no requirement for heating pumps shut off and fluid does not circulate and when there is no sunlight Systems therefore contain antifreeze to avoid freezing during this time If antifreeze solution is not circulating when subjected to solar radiation, solution can vaporise, damaging system Drain back systems slope pipework to allow fluid to drain back into tank under gravity This avoids risk of solution vaporising Also avoids risk of freezing thus negating requirement for antifreeze

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING Photovoltaic Cells Monocrystalline Silicon –Most PV Cells are monocrystalline type. –Made from single crystal of silicon –Highest efficiency – Typically 15% Policrystalline Silicon –Made from thin slices cut from a block of silicon crystals –Slightly lower efficiency – Typically 12% –Manufacturers claim that cheaper cost outweighs lower efficiency

LEVEL 4 RENEWABLE TECHNOLOGIESTRAINING Photovoltaic Cells Amorphous Silicon –Thin film made from very thin layer of semiconductor atoms on glass or metal base –Lowest efficiency – Typically 7% –Potential to be manufactured cheaply Dye Sensitised Thin Film –Light sensitive ink printed onto substrate –Low cost of manufacture –Typical efficiencies of %-2% –New technology only used in solar power generation plants currently –Supply not sufficient to commercial market currently

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING Examples of Solar Photovoltaire Systems

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING Wind Turbines Power Output is proportional to rotor swept area Power Output is proportional to the cube of the wind speed –Power = 0.5 x Swept Area x Air Density x Velocity 3 Wind turbines are not generally suitable for buildings in built up urban landscapes as they are not effective when situated close to other buildings, where wind speeds are generally lower and more disrupted A minimum wind speed is required to initiate the turbines. As such, average wind speeds for the area of the building should be assessed before making a recommendation

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING Wind Turbines

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING Combined Heat and Power (CHP) Parameters required for EPC calculations; Heat Efficiency; –Calculated as; Power Efficiency; –Calculated as; Heat to Power Ratio; –Calculated as; Total Annual Useful Heat Total Annual Fuel Energy Input Total Annual Power Output Total Annual Fuel Energy Input Heat Efficiency Power Efficiency

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING Combined Heat and Power (CHP) Building Space Heat & DHW Supplied; –This is a percentage of the heat and DHW load within the building which is supplied by the CHP generator –This value needs to be calculated by undertaking a previous detailed analysis considering the building heat demand values and patterns. SBEM is not a design tool, and as such all figures should be provided by Consultants for new build projects. For existing buildings, apply default values if information cannot be found. For further information consult the following; [1] Combined heat and power for buildings. Carbon Trust GPG388. [2] Small-scale CHP for buildings. CIBSE AM12 [3] Non-Domestic Heating, Cooling and Ventilation Compliance Guide. DCLG [4] Low or Zero Carbon Energy Sources Strategic Guide. DCLG

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING CHP GeneratorMicro-CHP Generator

LEVEL 4 HEAT PUMP – COOLING CYCLE STROMA Certification

LEVEL 4 HEAT PUMP – HEATING CYCLE STROMA Certification

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING Ground Source and Water Source Heat Pumps There are 4 main types of Ground Source or Water Source Heat Pump –Horizontal Closed Ground Loop –Vertical Closed Ground Loop –Vertical Open Loop –Closed Pond Loop Principle of ground and water source heat pumps is using refrigeration cycle to extract low level geothermal heat from the ground, groundwater or ponds Energy (heat) is extracted from the ground or water loop by an evaporator within the heat exchanger, compressed and then transferred to the heating system by a condenser Systems are effective due to stability of underground temperatures Can be used as preheat for LTHW central heating systems or commonly as the direct heat source for under floor heating, which requires significantly lower flow temperatures

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING Ground Source and Water Source Heat Pumps Horizontal Closed Ground Loop –Polyethylene pipe laid in trenches, typically 1m below the grounds surface –Large areas of free land required, ideally under a large car park for new builds –Mixture of water and glycol used as flow medium –Most cost effective method Vertical Closed Ground Loop –Where space is limited, vertical boreholes are prime option –Range from 25m – 150m –Potentially very expensive option –If boreholes are located too close to one another, permafrost can occur in the ground and render the system inactive and cannot be reversed Vertical Open Loop –Only cost effective if ground water is available and plentiful –Ground water is used as heat transfer medium and pumped through system Closed Pond Loop –No adverse impacts on aquatic system due to closed loop –Makes use of heat transfer from water and ground if achievable with body of water being primary source

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING Horizontal Closed Ground Loop Coil (or Slinky) Closed Pond Loop Coil Costly borehole digging rigBorehole pipework installation

Packaged Systems Unitary Packaged Units Indoor and outdoor components in self-contained ‘unitary’ package. Installed as ‘through the wall unit’. May be reversible heat pump. May have electric resistance heater.

Packaged Systems Individual Split Systems Also referred to as ‘split packaged units’. REFRIGERANT CIRCUIT COOLING INDOOR UNIT OUTDOOR UNIT HEAT REJECTION REFRIGERANT CIRCUIT

Packaged Systems Multi-Split Systems Also referred to as ‘multi-split packaged units’. REFRIGERANT CIRCUIT HEAT REJECTION MULTIPLE INDOOR UNITS SINGLE or MULTIPLE OUTDOOR UNITS DISTRIBUTION PIPES

REFRIGERANT CIRCUIT Packaged Systems Variable Refrigerant Flow (VRF) Systems Allows variable control of different branches. HEAT REJECTION MULTIPLE INDOOR UNITS REFRIGERANT CIRCUITS (CAN HAVE VARIABLE FLOW) BRANCH CONTROL MANIFOLD SINGLE or MULTIPLE OUTDOOR UNITS

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING expansion valve from energy sourcecompressor to energy source return from the heating system to the heating system condenser Heat Pump system Horizontal Closed Ground Loop Vertical Closed Ground Loop Vertical Open Loop Closed Pond Loop

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING Air Source Heat Pumps

Centralised Systems Distributed Heat Pump Systems Water loop/reversible heat pump systems Individual reverisble water-to-air heat pumps linked to common heat injection boiler and heat rejection cooling tower. Also known as ‘versatemp-type’ system. BOILER HEAT INJECTION DRY AIR COOLER HEAT REJECTION HEAT EXCHANGER

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING Heat Pump system and its end uses

LEVEL 4 RENEWABLE TECHNOLOGIES TRAINING ANY QUESTIONS OR FEEDBACK