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A brilliant overview by Anita Watts of all that you need to know to get you underway with the different technologies.
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Renewable EnergyAnita Watts
• FIRST - Energy Efficiency
• No point in generating renewable energy to waste it in energy
in-efficient homes and businesses
• Use renewables to attract attention to energy efficiency
Cost of energy
• Heating and powering homes
• Price at the pumps
• Cost of food etc…
• Renewables started to be looked at seriously in 1970’s
Renewable energy technologies
Heat ? Electricity ?
HEAT•Solar water heating panel
• Wood fuels
• Biomass crops
• Wood combined heat and power (CHP)
• Anaerobic digestion
Source: Easy heat systems
• Ground source heat pump
• Air source
• Water source
• Geothermal plant
• Solar photovoltaic panel (PV)
• Solar photovoltaic panel (PV)
Source: Greengage
• Micro hydro plant
Source: Greengage
• Hydro dams
Source: EST
• Wave power, using the motion of waves on the surface of the sea
• Pelamis Wave Energy Converter
Source: EST
• Wave power
• Tidal power, using the movement of the tides.
• Tidal power, using the movement of the tides.
Source: EST
• Tidal Barrage in Bretagne, France
• Wind turbine
• Wind farm
Solar water heating
Domestic hot water
• Do we get enough sun for solar thermal systems to work here?
• Active solar heating systems will typically convert 30–60% of the solar energy falling on the solar collectors into useful heated water
• 4m2 system can offset 1800 kWh / year
• 25 years – 45,000 kWh
• Oil at 64p/l = 7.38p/kWh (85% efficiency)
• £3321
1. Should face south, or between SE and SW
2. Tilted ideally 30–45 degrees
3. Avoid shading
4. Room for a larger storage cylinder
5. Keep run distances short
6. Meets about 40–60% of DHW demand
7. Needs conventional water heating as back up
8. Use accredited installers
9. RHI to follow
Premium payment grant
Renewable heat incentive
•Non Domestic
•Domestic
– TBC
– 20 years = 36,000kWh @ 8p = £2880 (index linked)
Wood fuels
Space heating & hot water
Types of wood biomass fuel
• Forestry residue or tree thinning
• Seasoned logs burn well• A bulky fuel which needs a
lot of storage space • Hard to handle • Manual processing• Manual loading and
lighting• Relatively cheap or free
source of fuel• Hardwoods provide more
energy than softwoods as they are more dense
Logs
• Made from sawdust
• Lignin binds the pellet
• High-quality fuel
• High-energy density
• Uniform
• 2.5-cm long, 6-8mm diameter
• Moisture < 10%
• Ash < 1%
• Most processed of the wood fuels - cost
• Pellets can also be made from willow, hemp, straw etc… for multi-fuel boilers
Pellets
Source: Viesmann
Pellet system• Pellets are delivered by
tanker usually once or twice a year
• They are blown into the pellet store
• The pellet are moved from the store to the boiler by a fully automated feed system
• All that is left is <1% of the pellets as ash
• The well insulated buffer hold the hot water until it is needed for heating radiators or domestic hot water
• Forestry residue, coppicing, waste wood
• Most bulky of the wood fuel so they need the most storage space
• 40-km supply radius
• Supply contracts
• Moisture < 20%
• Waste wood contamination
• Relatively cheap fuel
• Boilers are expensive
• Best for large heat demands
Chips
Pellets example
Pellets 4.66p / kWh
Premium payment grant
Renewable Heat Incentive
•Non Domestic
•Domestic – TBC
– 25,000 kWh heat demand – Pellets: 4.66p / kWh = £1,165– Oil: 7.38p / kWh = £1845– RHI payment = £1,600 (index linked for 20 years)
Heat pumps
Space heating & maybe hot water
• Heat pumps types are generally classified and described based on the source of stored heat they tap into
• There are four main types:
– Ground source heat pump (horizontal and slinky)
– Bore hole heat pump (vertical)
– Water source heat pumps (open and closed)
– Air source heat pump
(Ambient and exhaust)
• Coefficient of performance (CoP) is the ratio of useful heat energy output to electrical energy input
• A CoP of 3 means that for every 1kWh of electricity input you will get 3kWh of heat output
• The energy required to concentrate heat is much less than the energy which must be liberated by burning a fuel
• Make sure that the building is as well insulated as possible.
• Install the heat pump with low temperature underfloor heating or low temperature radiators.
• The heat pump must be correctly sized and all elements installed to the manufacturers recommendations
• Insist upon understandable, user-friendly controls with a detailed customer handover.
• Keep it simple. The field trial findings categorically show that the simplest system designs achieve the best efficiencies.
• Responsibility for the installation should be with one company, and ideally be contractually guaranteed to ensure consistency in after-sales service.
Premium payment grant
Renewable Heat Incentive
•Non Domestic
•Domestic – TBC
– 25,000 kWh heat demand – Heat pump (COP:3) ~8.53/kWh (E7 85%) = £710 (+18%)– Oil: 7.38p / kWh = £1845– RHI payment = £2,175 (index linked for 20 years)
Solar electric PV
Source:Greengage
• PV
• Electricity generated by the system works hand in hand with the existing electrical supply to power the household appliances and lighting
• There will be import and export of electricity
• Grid connected
• Stand alone
Grid-connected systems• NIE Network
• Connection to a high technical standard
• Upgrades may require planning permission
• Upgrades may incur costs
• An import export meter must be installed to sell electricity
• Secondly, the turbine must shut down if there is a grid power failure.
• Current EU legislation - Protect maintenance personnel
• Not a backup in a power cut.
• Behaviour change
• Maximise usage of electricity during the day
• Timers and programmers
• Clean power source
• Reduces bills
• Increases awareness
of electricity use
• Increases the value
of your property
• Extremely low
maintenance
• Long functional
lifetime of 25yr +
• Silent in operation
ROCs
•Renewable Obligation Certificates
• 4 ROCs for every 1000kWh generated
•Tradable commodity
•17.64p / kWh
• Economics in NI
• Up to 50kWp
• ROCs = 17.64p• Spill = 5.41p• Save = 14-15p (+18%)
• 4kWp system– Approx.: 7year payback– £20,000 lifetime savings
Wind power
Vertical-axis style
Horizontal axis
• Most large wind farm turbines are the traditional three blade horizontal wind turbines
• Common sizes of domestic wind turbines are in the range 2.5–20kW.
• Antrim area hospital’s 660kW turbine
• Offshore wind farms
• 3 – 5 MW
Site Factors
• Altitude - The higher the better – higher wind speeds
• Aspect - Ideally SW slopes, coastal, open terrain
• Obstructions/turbulence - buildings, trees, hills, cliffs
• Access - For erection, maintenance
• Space/Proximity to dwellings - Noise, flicker, room to erect
and maintain, cable run, planning, environmental, visual
• Demand profile - Load factor, timing of demand
• Grid - distance, three phase/single phase
NIROC Support bands for Wind
• Up to 250kW
• 4 ROCs - 17.64p/kWh
• 250kW – 5MW• 1 ROC - £44.10/MWh
Micro hydro power
Source: British Hydro Association
• Power can be captured wherever a flow of water falls
• By the end of the 19th Century there were over 30,000 watermills in Britain
• Head - H
• Flow - Q
Advantages of Hydropower
• High capacity factor (typically towards 50%)• A high efficiency (70 - 90%), by far the best of all energy
technologies.• A high level of predictability, varying with annual rainfall
patterns• Slow rate of change; the output power varies only gradually
from day to day (not from minute to minute).• A good correlation with demand i.e. output is maximum in
winter• It is a long-lasting and robust technology; systems can readily
be engineered to last for 50 years or more
Up to 20kW
4 ROCs = 17.64p/kWh
20-250kW
3 ROCs = 13.23p/kWh
250-1MW
2 ROCs
• Oil reserves to production ratio – 54 years
• Oil reserves to production ratio – 54 years
• Gas reserves to production ratio – 64 years
• Oil reserves to production ratio – 54 years
• Gas reserves to production ratio – 64 years
• Coal reserves to production ratio – 112 years
• Renewables accounts for 3.9% of global power generation, with the highest share in Europe and Eurasia
• An unlimited resource
• In abundance in Northern Ireland
Source: Association for the study of peak oil
• Dr Colin Campbell – peak oil expert
• As resources become scarce the become more expensive
Source: Association for the study of peak oil
Security of supply
• 98% of the energy in NI is imported
• End of a long supply chain
• £2.3B spent on energy in NI every year
Source: Association for the study of peak oil
Environmental
• Carbon emissions
• Green house effect
• Global warming
• Climate change
• Weather chaos
Source: Association for the study of peak oil
Environmental
• Carbon emissions
• Green house effect
• Global warming
• Climate change
• Weather chaos
Targets
• 15% of energy, including electricity, heat and transport, from renewable sources by 2020
• 2050 decarbonisation of the electricity network and all buildings are carbon neutral
