Domestic Green Deal Advice Training

Transcription

1 Domestic Green Deal Advice Training Renewables and Microgeneration

2 The Measures 2

3 Renewable energy Renewable energy is energy which comes from natural resources, naturally replenished. In its various forms, it derives directly from the sun, wind, water or from heat generated deep within the earth. Included is electricity and heat generated from solar, wind, ocean, hydropower, biomass, geothermal resources, biofuels hydrogen derived from renewable resources

4 Passive solar design What Passive solar design refers to the use of the sun s energy for the heating and cooling of living spaces. In this approach, the building itself or some element of it takes advantage of natural energy characteristics in materials and air, created by exposure to the sun. Passive systems are simple, have few moving parts, and require minimal maintenance and require no mechanical systems Passive design is practiced throughout the world and has been shown to produce buildings with low energy costs, reduced maintenance, and superior comfort Any design feature that maximises insulation and uses free solargain will be most cost effective in reducing the energy bills of a building over its whole life span.

5 Passive solar design Recognising passive solar design Passive solar design involves a range of features such as: double or triple-glazed south-facing windows -which allow infrared radiation to pass through -plus smaller north facing windows to minimise heat loss light tubes which channel sunlight from an outside roof or wall into a room during the day Trombe walls this is a natural design features which moves air warmed by free solar heat into a space using convection a double-glazed conservatory or a solarium. In hotter months, conservatories can be shaded and naturally ventilated to protect from excess heat and ultraviolet rays.. By closing doorsat sunset, heat loss is prevented from the main building, using well insulated doors or windows The need for dynamic simulation modelling put it outside the scope for SAP

6 Heat Pumps

7 Heat pumps Air source heat pumps absorb heat from the outside air. This heat can then be used to heat radiators, underfloor heating systems, or warm air convectors and hot water in your home. An air source heat pump extracts heat from the outside air in the same way that a fridge extracts heat from its inside. It can get heatfrom the air even when the temperature is as low as --15 C. Heat pumps have some impact on the environment as they need electricity to run, but the heat they extract from the ground, air, or water is constantly being renewed naturally

8 Heat Pumps Ground source heat pumps use pipes which are buried in the garden to extract heat from the ground. This heat can then be used to heat radiators, underfloor or warm air heating systems and hot water in your home. A ground source heat pump circulates a mixture of water and antifreeze around a loop of pipe -called a ground loop -which is buried in your garden. Heat from the ground is absorbed into the fluid and then passes through a heatexchanger into the heat pump. The ground stays at a fairly constant temperatureunder the surface, so the heat pump can be used throughout the year -even in the middle of winter

9 Heat Pumps to the heating system compressor from energy source condenser Horizontal Closed Ground Loop Vertical Closed Ground Loop return from the heating system expansion valve to energy source Heat Pump system Vertical Open Loop Closed Pond Loop

10 Heat pumps Advantages could lower your fuel bills, especially if you replace conventional electric heating could provide you with an income through the government s Renewable Heat Incentive (RHI) could lower your home s carbon emissions, depending on which fuel you are replacing don't need fuel deliveries can heat your home and provide hot water need little maintenance - they're called fit and forget technology

11 Heat pumps Dis-advantages Lower heat out put than conventional system High installation cost Works better with an insulated dwelling Need space externally to fit the unit Performs best with underfloor heating due to lower water temperatures

12 Changing to a heat pump Consideration need to be given when changing from a boiler to a heat pump Specialist calculation would need to be undertaken to determine fabric heat losses and heat emitter sizes Due to the lower flow temperature of heat pumps compared to boilers, the radiators may be under sized.

13 Biomass (and Biofuels)

14 Bio mass Wood-fuelled heating systems, also called biomass systems, burn wood to provide warmth in a single room or to power central heating and hot water boilers Abiomass boilerconnected to a central heating and hot water system. A wood-fuelled boiler could save you nearly 600 a year compared to electric heating.

15 Solid fuel Traditional Solid Fuels: Coal can be used in open and closed room heaters cannot be used in Smoke Control Zones Anthracite used as a replacement for coal in Smoke Control Zones Supplied in grains or nuts, smaller than coal Can be used in solid fuel central heating boilers Smokeless fuel Used as a replacement for coal in Smoke Control Zones Can be used in open and closed room heaters Much more expensive than coal Is a manufactured fuel, the coals are usually a uniform shape

16 Solid fuel Biomass Comes in various forms Wood logs Wood chips Wood pellets When biomass fuel is combusted is releases carbon dioxide, but no more than it absorbs whilst the tree grows. Biomass is therefore considered to be carbon neutral Wood pellets and wood chips can be used in biomass boilers Wood logs are used in open and closed room heaters

17 Biomass & Biofuel Boilers

18 Bio mass Advantages Affordable heating fuel ( price varies) low-carbon option ( considered carbon neutral) Financial support Variety in fuels ( logs, chips, pellets ) Theoretically inexhaustible fuel source Disadvantages Potential to run out of fuel Flue/chimney will need sweeping regularly Ash needs to be removed from the system periodically Expensive installation cost Storage of fuel is needed Still an expensive source, in terms of producing the biomass Not appropriate for all dwellings

19 Biomass and Biofuel Biomass can be burnt directly to provide heat in buildings. Woodfrom forests, urban tree pruning, farmed coppices or farm and factorywaste, is the most common fuel and nowadays is used commercially in the form of wood chips or pellets, although traditional logs are also used. Biomass boilers can be designed to burn smokeless fuel to complywith the Clean Air Acts. Boilers can be fed automatically by screw drives from fuel hoppers. This typically involves daily addition of bagged fuel to the hopper. Electric firing and automatic de-ashing are also available. Biomass boilers replace conventional fossil fuel boilers and come with the automated features mentioned above. Fuels other than wood, suchas straw can also be used.

20 Biomass and Biofuel Biomass is normally considered a carbon neutral fuel, as the carbon dioxide emitted on burning has been (relatively) recently absorbed from the atmosphere by photosynthesis and no fossil fuel is involved. The wood is seen as a by-product of other industries and the small quantity of energy for drying, sawing, pelleting and delivery are discounted. Biomass from coppicing is likely to have some external energy inputs, for fertiliser, cutting, drying etc. and these may need to be considered in the future.

21 Bio mass Savings in carbon dioxide emissions are very significant -around 7.5 tonnes a year when a wood-fuelled boiler replaces a solid (coal) fired system or electric storage heating. Financial savings are more variable

22 Solar Thermal

23 Solar thermal What is solar thermal technology Simply -Solar thermal systems heat water using the energy from the sun, which can then be stored for use in domestic, public or commercial buildings.

24 Solar thermal How does it work A closed circuit of pipes, powered by a digitally controlled pump, transports the heated transfer fluid to a coil in the hot water cylinder, which then stores the heated water for later use

25 Solar thermal

26 Solar thermal Flat plate collectors: A flat-plate collector consists of an absorber, a transparent cover, a frame, and insulation. Usually an iron-poor solar safety glass is used as a transparent cover, as it transmits a great amount of the short-wave light spectrum.

27 Solar thermal Evacuated Tube collectors In this type of vacuum collector, the absorber strip is located in an evacuated and pressure proof glass tube. The heat transfer fluid flows through the absorber directly in a U-tube or in counter-current in a tube-in-tube system. Several single tubes, serially interconnected, or tubes connected to each other via manifold, make up the solar collector. A heat pipe collector incorporates a special fluid which begins to vaporize even at low temperatures. The steam rises in the individual heat pipes and warms up the carrier fluid in the main pipe by means of a heat exchanger. The condensed liquid then flows back into the base of the heat pipe.

28 Solar thermal Unglazed Panels A solar collector that consists of an absorber without the glass covering of a glazed flat-plate collector. Generally used when high rate temperatures are not required. E.g. Swimming pool

29 Solar thermal Installer requirements To get the most from a solar thermal system just like solar PV, the collector is best sited on a roof facing from east through west, with south being optimal. The roof structure would need to be in generally good condition(free from defects)and the roof covering intact. The system would need to be compatible with the existing heatingsystem and the solar thermal system sized appropriately to the heating system and the occupants of the property The system will need a thermal storage to enable the heat to be exchanged. so combination boiler systems are not usually used in conjunction with a solar thermal system. Panels usually would fall under permitted development rights

30 Solar thermal Installer requirements Access to the roof would be obtained through scaffolding so this would need to be taken into account on a installer survey The panels would also need to be lifted to the scaffold platform lifting bag e.g. Using a Pafbag

31 Solar thermal Typical efficiency's for solar thermal will be around 60% With the majority of the hot water generated in summer Solar thermal panels even operate in low light conditions ( cloudy days ) to good effect (1/3 rd ) However in the UK you will always need an axillary heat source. In installing solar thermal there would need to be a enough room for the cylinder

32 Solar thermal The general rule of thumb is half a solar thermal panel per person. Various effects have a impact on the amount of heat the panels are able to produce. E.g. Orientation Over shading Pitch Location in country

33 Solar thermal Maintenance Maintenance costs for solar water heating systems are generally very low. Most solar water heating systems come with a five-year or tenyear warranty and require little maintenance In general you should keep an eye on your system to check that it is doing what it has been designed to do. You should have your system checked more thoroughly by an accredited installer every 3-7 years to have the Pump checked Anti freeze topped up

34 Solar PV

35 PV What is solar PV? Solar PV panels utilise the sun s energy and convert it into free, renewable electricity that you can use to power lighting systems and appliances in your home. PV produces electricity by converting sunlight using the photoelectric effect.

36 PV Light (protons) literally knocks electrons out of the semiconducting material Most PV is made from Silicon

37 PV This technology has been used since the late 50 s in the space industry to power satellites and since the 70 s in solar powered calculators The first solar powered satellite launched in 1958 is still in service

38 PV There are three types of silicon cells: 1. Monocrystalline 2. Polycrystalline 3. Amorphous There are also hybrid PV cells combining a layer of amorphous silicon over a monocrystalline, (e.g. Sanyo)

39 PV Monocrystalline cells are cut from a single crystal of silicon. Cylinders of silicon are sawn into very thin slices called wafers, the thickness of a human hair. Due to the delicate and labour intensive manufacturing process these cells are the most expensive to make. However, they are also the most efficient with a range of 15% to 18%.

40 PV Poly or multicrystalline silicon cells are cut from a block of silicon that is made up of a large number of crystals. The cells are completely square unlike monocrystalline cells. Due to the impurities between the crystals those cells are slightly less efficient, having a range of 14% -15%. However they are cheaper to manufacture.

41 PV Amorphous cells are manufactured by placing a thick film of amorphous (noncrystalline) silicon onto a wide choice of surfaces. This is flexible and can be mounted onto a curved surface. This is the cheapest form of silicon cell but also the least efficient 6%-8%. Although less efficient this type of panel may be more efficient in cloudy conditions, this is the type of cell that is used in small devices.

42 PV First the inverter transforms the electricity generated by the panel from direct current (DC) into alternative current (AC). The electricity is then used as normal by the electrical appliances such as lights, computers, fridges etc. When the systems produces more electricity than needed the power is sold back into the grid via an export meter. However when the system doesn t produce enough or no electricity (at night for example), the electricity is imported from the National Grid as normal.

43 PV Unlike solar thermal PV is much more susceptible to light conditions, orientation and pitch of the panels. The 3 factors do have an effect on the amount of energy that the system is able to create Optimum conditions South facing 30 pitch Un shaded

44 PV Overshading Extract from SAP

45 PV Orientation and pitch

46 Over Shading Ideally no over shading should occur As normally cells are connected in a string a small amount of over shading will affect the whole panel or module. The examples to the right show partial shading that can reduce the module efficiency by 50%.

47 PV Installer requirements Similar requirements are needed to install PV as solar thermal however more panels will usually be installed with a PV system due to the lower efficiencies. There is also the benefits of the Feed in Tariffs, however these are not taken into account for Green Deal.

48 Wind Turbines

49 Wind Turbine The UK benefits from some of the highest average wind speeds in Europe, making it an ideal candidate for wind energy. The technology now generates around 2.5% of the UK s electricity and the proportion is increasing rapidly. Between 2007 and 2009 the amount of electricity generated from wind power in the UK increased by over 75% and in 2010 accounted for 58% of all UK renewable electricity generation.

50 Wind Turbine There are two main designs of wind turbine those with a horizontal axis and those with a vertical axis. Most turbines for homes have a horizontal axis whilst they can be mounted directly on a building, turbines mounted on free-standing towers or poles can be more effective at capturing the wind s energy.

51 Wind Turbine A typical 1kW building mounted system costs approximately 2,000 including installation. A typical 2.5kW pole mounted turbine costs around 15,000 and a 6kW pole mounted system costs approximately 23,000 to install. Savings will depend on the turbine type size, local wind conditions, economies of scale and the cost of the electricity being replaced by using the wind turbine. Rural or coastal dwellings can benefit more easily from wind energy as local wind conditions are often good.

52 Wind Turbine Building mounted turbines are a new type of wind turbine designed to be installed directlyonto a building. This means you avoid the costs of having a free standing tower and foundations. Designs of these systems vary between manufacturers and include both vertical and horizontal axis machines. However, a building mounted turbine will not normally generate as much electricity as an equivalent pole or tower mounted machine.it may also add stress to your home s building fabric due to increased weight and vibrations. You should always seek specialist guidance before installing a building mounted turbine.

53 Micro Combined Heat and Power (Micro-CHP)

54 Micro-CHP Micro-CHP stands for micro combined heat and power. Heat your home and generate electricity at the same time with a micro- CHP unit. This technology generates heat and electricity simultaneously, from the same energy source, in individual homes or buildings. The main output of a micro-chp system is heat, with some electricity generation, at a typical ratio of about 6:1 for domestic appliances. 54

55 Micro-CHP A typical domestic system will generate up to 1kW of electricityonce warmed up: the amount of electricity generated over a year depends on how long the system is able to run. Any electricity you generateand don't use can be sold back to the grid. You should expect to pay between 5,000-6,000 to have a Micro CHP boiler installed. 55

56 Micro-CHP Advantages Electricity generation as a by-product of heat. When the micro-chp is generating heat, the unit will also generate electricity to be used in yourhome (or exported). Carbon savings. By generating electricity on-site you could be saving carbon dioxide compared with using grid electricity and a standard heating boiler. Financial income. Micro-CHP is eligible for Feed-in Tariffs and you will earn 11.0p for each kwh of electricity generated by your system. You will also receive 3.2p for each kwh of electricity you export. Installation is easy. For the householder, there is very little difference between a micro-chp installation and a standard boiler. If you already have a conventional boiler then a micro-chp unit should be able to replace it as it s roughly the same size. However, the installer must be approved under the Microgeneration Certification Scheme. Servicing costs and maintenance are estimated to be similar to a standard boiler although a specialist will be required.

57 Micro-CHP Dis advantages Micro CHP is a relatively unproven technology Carbon savings in most smaller, newer domestic properties are insignificant Micro CHP is inefficient for short run cycles. There is a high incidence of unreliability in currently installed units On average, 50% of electricity generated in domestic applications is surplus. There is a current shortfall of available export reward tariffs for excess electricity directed to the grid. Current life expectancy of micro-chp units is reported to be relatively low High installation costs Some CHP units are heavy requiring solid flooring Current payback period is in excess of 20 years, but will reduce along with increased production

58 Any Questions