Introduction to Farm Renewables - Paul Holmes-Ling (Laurence Gould Partnership)

Renewable technologies overview - do they work?

Paul Holmes-Ling CEnv.

Introductions

Paul Holmes-Ling CEnv.

• Environmental Consultant for the last 12 years.

• Working primarily with farmer, landowners • Working primarily with farmer, landowners and tourism businesses.

• Currently involved with a wide range of energy related projects.

What are we going to cover?

• Solar

• Heat pumps

• Small scale hydro

• Wind• Wind

• Biomass

• Biogas

Consider…

What are your Efficiencies

What

Heat

£

energy requirements

Efficienciesfirst

resources are available

Heat and power

Power

Renewable Energy - Introduction

Heat PowerHeat

Combined heat and Power (CHP)

Power

Renewable Energy - Introduction

1 definition - ‘Using natural replenishableresources to create energy’

• Sunlight

• Water

• Wind

• Biomass

• Biogas

• Heat pumps

Renewable Energy - Solar

Introduction

• Energy derived from the sun

• Passive heat – this is heat derived naturally from the sun and can be taken into account during building design to reduce heating costsbuilding design to reduce heating costs

• Solar thermal – the suns heat is used to provide hot water

• Photovoltaics (PV) – using the suns energy to create electricity.


Passive heat

• Incorporating features into buildings that absorb and then slowly release heat

• No mechanical parts!• No mechanical parts!

• For example large windows, stone floors.

• Can save 50% of energy costs within a new build and often adds nothing to the capital cost.


Passive heat


Passive heat – case study – Brighton Earthship (www.lowcarbon.co.uk)


Solar thermal - background

• Available since the 1970s – technology well developed, proven

• Large choice in the market place

• One of the cheapest renewable options

• Can provide all hot water during the summer and about 60% year round

• Quick carbon payback

• ‘normally’ considered permitted development

• 30 – 40 % efficient


Solar thermal – what do you need?

Renewable Energy - Solar Solar thermal – case study

Dairy Farm – Oxfordshire

• 130 dairy cows

• Main electricity use is heating a 300 litre water storage • Main electricity use is heating a 300 litre water storage tank – used for twice daily cleaning = 70% of energy use

• Electricity also used for cooling milk (and lighting etc.)

• Electricity use is 40,000 kWh day rate units and 20,000 kWh night rate units = 462kWh per cow

• Annual electricity spend = £5400



• 2 roof mounted solar panels (2.4m2)

• 300 litre dual coil storage system

• Controller unit

• Pump

• TOTAL cost £4000



• Annual energy savings of 50% of water heating costs = £1890

• Payback = 2.5 years or 47% return!• Payback = 2.5 years or 47% return!

Renewable Energy - Solar Solar thermal – typical costs

• Costs vary depending on the technology used however the sizing is usually worked out on the size of the ‘buffer’ tank required.

• 200 litre tank and 2.2m2 of evacuated tubes - £3,000

• 500 litre tank and 5.4m2 of evacuated tubes - £5,000

• Flat plate collectors tend to be cheaper than evacuated tube systems, but are less efficient particularly in the winter months when the heat is needed!

• Important to consider the length of guarantee offer ed


Photovoltaics (PV) – How does it work?

• 1 or 2 layers of a semi conducting material (usually silicon)

• Light shines on the cell and creates an • Light shines on the cell and creates an electric field across the layers

• The greater the intensity of light the greater the flow of electricity.

• Efficiency is 12 – 17% depending on materials used.


Photovoltaics (PV) – Background

• Easy to integrate into new and existing buildings

• Virtually no maintenance

• Rapidly improving technology • Rapidly improving technology

• Long life with no moving parts

• Most expensive micro renewable technology – long paybacks

• Needs large roof space area and aspect between SE and SW.

• Good for small off grid situations

• Can be combined with other renewable technologies


Photovoltaics (PV) – case study 1

Green ‘wedding and function’ venue

• Converted barn

• Used on average twice a week for events

• Annual electricity usage – 4500kwh


Photovoltaics (PV) – case study

• Solution a 5.5 kw peak PV system installed

• 45m2 of roof spaced required• 45m2 of roof spaced required

• Meters upgraded

• Potential output (5.5 X 850) = 4675kwh

• Cost £30,000

Renewable Energy - Solar Photovoltaics (PV) – case study

Expenditure £

TOTAL Capital cost 30,000

Annual Income

ROCS 420 4675 *9p (based on 2 ROCS – see energy

income section)

Annual Savings 467.50 Presuming all electricity is used on site.

Energy price of 10p / kWh has been used

TOTAL Income and

savings

887.50

Payback 33 years

• 50% grant achieved through LEADER

• Key benefit is through marketing as a green venue – PV is highly visible


Photovoltaics (PV) – typical costs

A typical system providing half an average families annual electricity supply, typically covering 10-15m² of roof space and generating 1.5- 2kWp (kilowatt peak) would cost between £4000 and £8000 per kWpwould cost between £4000 and £8000 per kWpdepending on the site and materials used.

A typical small off grid system producing 500Wp (with a 24Vdc, 400Ah battery and 900W inverter and all wiring) would cost around £5,000. This system would provide enough power for a small building for example a shed or equestrian building with 5 20W low energy bulbs (each on for 5 hours a day)

Renewable Energy – Heat pumps

Heat pumps - background

• Heat pumps use the same technology as refrigerators but in reverse, moving heat from one place to another. Ground Source (GSHP), Air Source (ASHP) and water (WSHP)Source (ASHP) and water (WSHP)

• Heat pumps can provide space heating, cooling and water heating.

• Heat pumps are not truly renewable as the working fluid is driven around the system by an electrically powered pump

• Very good paybacks achieved

• There is a heat pump to fit most circumstances and budgets


Heat pumps – background

• 3-5 times more efficient than a conventional boiler

• A GSHP can provide up to 100% of a buildings heating requirement – therefore no back up system required. ASHP may only provide 60 – 70% required. ASHP may only provide 60 – 70% therefore back up system required.

• No planning required in most cases.

• GSHP not easy to retrofit. ASHP are.

• Requires a ‘wet’ heating system ideally under floor heating

• Reliant on grid electricity (unless attached to another renewable technology)


Ground Source Heat pumps

• In the UK the ground a few feet below our feet maintains a constant temp. of 11 – 12ºC year round

• GSHP transfer this heat into a building to provide space heating and occasionally hot waterspace heating and occasionally hot water

• For every unit of electricity used to pump the heat 3-4 units of heat are produced.

• To be 100% renewable you would need to generate your electricity from a ‘renewable source.

Renewable Energy – Heat pumps Heat pumps work by:

• Refrigerant in the evaporator is colder than the heat source, therefore heat moves across causing refrigerant to evaporate.

• The vapour moves to the compressor, where it reaches a higher temp and pressure.reaches a higher temp and pressure.

• The hot vapour enters a condenser and gives off heat as it condenses – this is transferred to the heating system.

• The refrigerant then moves to the expansion valve, where it drops in pressure and temperature and returns to the evaporator.

Renewable Energy – heat pumps

GSHP what do you need?


Air source pumps

• As the temperature variations are greater, the COP (coefficient of performance) declines with temperature.

• Therefore more electricity is required.• Therefore more electricity is required.

• Usually can provide 50-75% of heating requirement (Ground source 75-100%), and therefore more likely to utilise other heating sources.

• Shorter life than ground source as more ‘exposed’ parts

• However suitable for many applications


water source pumps

• Requires a water body!

• Very efficient if groundwater used

• Open water less efficient (greater COP as • Open water less efficient (greater COP as greater temp. variation)


GSHP – case study

• Plumpton College – new science centre

• Requirement for heating (620m2) and hot water (35-40ºC)water (35-40ºC)

• Field adjacent to building


GSHP – case study

• Viessman heat pump

• ‘Wet’ under floor heating system

• 200L buffer tank (with immersion heater)

• 300ms of coil in 6 - 50m trenches, 1.8m deep and 30cm wide with 5 m separation –total area = 1340m2 = 0.134ha


GSHP – case study

Heating system Capital cost Economic life 10yr lifetime fuel cost 10 year lifetime cost annual CO2 poduction (Kg)

GSHP 35,000 20 27,190 62,190 195

31kw LPG boiler 6,500 15 133,134 139,634 503

10 year savings 105,944

annual savings 10,594annual savings 10,594

Payback 3.03 years

Assumptions:

30.7kw heat load

annual energy consupmption 2071kWh/ year

electricity @ 6p kWh

LPG @ 4.5p kWh

GSHP includes £16,000 for ground works

COP (coeficience of performance) of around 4.57 - therefore with electricity at 6p for every 1kwh of thermal energy produced

only 1.31p of electricity will be required


GSHP – ‘typical costs’

A typical system to heat a 3 bedroom house would require an 8kW system, which would cost in the range of £800 - £1400 per kW of peak output with trench systems being at the lower end of the range. Typical systems being at the lower end of the range. Typical installed cost of an 8kW system would be between £8000 and £14000 plus the cost of the distribution system (ideally underfloor heating).

An equivalent air source system would cost between £500 - £700 per peak kW output, but has a lower COP and cannot provide year round heating requirements meaning more electricity or alternative heating source will be required.

Renewable Energy - Wind

Wind turbines - background

• Converting the power of moving air into rotating shaft power and electricity

• Power from the wind is proportional to the wind speed – small variations make a big difference to speed – small variations make a big difference to output

• Big variations in turbine sizes from a few hundred watts to 2- 3MW

• Wind turbines create a DC supply. Needs a ‘converter’ to change to AC.

Focus on wind

The UK wind resource

• We have 40% of Europe's total wind energy resource!

• Largely untapped – currently meeting 0.5% of our electricity requirementselectricity requirements

• It is theoretically possible to obtain 1000TWh or electricity per annum – 3 times the UKs total energy demand!

• Practically, due to protected areas, residencies, grid strength and economics we could achieve 50TWh per annum (on land)


Wind turbines – how do they work?


Wind turbines – local wind conditionsWind speed at 10m above ground level (m/s)

5.6 5.6 5.3

5.3 5.7 5.5

5 5.6 5.7

Wind speed at 25m above ground level (m/s)

• Available on NOABL wind database –www.bwea.co.uk


6.4 6.4 6.2

6.2 6.5 6.3

5.9 6.4 6.5


6.9 6.9 6.8

6.7 7 6.8

6.5 6.9 6.9


Wind turbines – local wind conditions –what does this mean?

• Power generated is related to wind speed by a cubic ratio.

• Therefore if you halve wind speed the power goes • Therefore if you halve wind speed the power goes down by a factor of 8 (2 X 2 X 2), a quarter of the windspeed gives you a 64th of the power (4 X 4 X 4).

• Really need an average wind of over 6m / s

Focus on windTypes of turbine

• Big variations in turbine sizes from a few hundred watts to 3MW

Make / mode Swift 1.5 Proven 2500 Proven 6000 Westwind 20 WinWind 1

rating 1500Wp

1.5kwp

2500Wp

2.5kwp

6000Wp

6kwp

20000wp

20kwp

1MWp

Height (m) 1.75 10m 15m 18 70

Blade diameter

(m)

2.1 3.5 5.5 10.4 60

Expected energy

production – per

annum

1031kwh 3164kWh 7805kwh 23,000kwh 1,000,000kwh

Cost (£) 1,600 10,900 22,000 50,000 350,000

No. of

households!

0.2 0.8 2 6 90


Planning

• Usually requires planning permission from local authority

• Planners will consider visual impact, noise • Planners will consider visual impact, noise and conservation.

• Discuss with your planner early!

Focus on wind

Case study – 20kwp westwind turbine

• Farm in Chichester – good average winds of 13 m /s at 15m.

• Large energy requirement for student • Large energy requirement for student accommodation and offices (anemometer)

• Turbine size based on how much they wanted to spend and paybacks!

Focus on wind

Case study – 20kwp westwind turbine


Case study – 20kwp turbine

• 15m tower plus 10m blades

• Costs £40,000 + 10,000 for cabling plus £1,500 annual maintenance.£1,500 annual maintenance.

• Produced 30,000kWh per annum


Case study – 20kwp turbine

Expenditure £

TOTAL Capital cost 50,000

Annual Income

ROCS 2,700 30,000 *9p (based on 2 ROCS 2,700 30,000 *9p (based on 2

ROCS )

Annual Savings 3,000 Presuming all electricity is

used on site. Energy price

of 10p / kWh has been

used

TOTAL Income and

savings

5,700

Payback 9 years


Bigger = better paybacks

Expenditure 20kwp 6kwp

TOTAL Capital cost 50,000 30,000

Annual Income

ROCS 2,700 702ROCS 2,700 702

Annual Savings 3,000 780

TOTAL Income and

savings

5,700 1,482

Payback 9 years 20 years

If wind conditions good and you can use or sell all the energy


Case study 2 – large turbine – Westphalia - Germany

• 7 farmers formed a co – op

• 65m capable of producing 1,000,000kWh per annumannum

• Actually produces 600,000 – 700,000 kWh per annum

• Capital cost E500,000

• Energy is supplied to local village (average house uses 3000kW per year)


Case study 2 – large turbine – Westphalia – Germany

Income £ Notes

Electricity sales 60,000 1000MW @ £60MWLECs 4,0001000MW @ £4MWROCs 39,0001000MW @ 39MWTOTAL SALES 103,000

ExpenditureRent 1,000Maintanence £6,700Depreciation 17,000Finance 17,600Total Over heads 42,300

Net Margin 60,700


Case study 3 – Chicken Farm Berkshire• ‘Off grid’ system

• 500 bird units

• 24 hour lighting required in early • 24 hour lighting required in early stages of life

• Houses regularly moved

• Cost of grid connection 50K +


Case study 3 – Chicken Farm Berkshire


Case study 3 – Chicken Farm Berkshire

• Combined wind and solar system

• 270Ah deep cycle battery – (can store 3 days worth of energy)days worth of energy)

• Whole system is mobile

• Cost £5000 per chicken house


Typical costs

• Including mast, inverters, turbine and installation would range from £2,000 for a 1kw system average estimated power output per year to £18,000 for a 6kw output per year to £18,000 for a 6kw system.

• A 1MW system may cost in excess of £350k

Renewable Energy – small scale hydro

Small scale hydro - background

• The oldest method of harnessing renewable energy

• Uses the stored ‘kinetic’ energy to turn a turbine • Uses the stored ‘kinetic’ energy to turn a turbine and create electricity

• Allowances need to be made for seasonal variations

• Efficiency is 50 – 90% depending on system

• Energy source is ‘predictable’


Small scale hydro - background

• Micro hydro refers to systems producing less than 100kWh

• 2 kinds of system

• ‘low’ and ‘high’ head

• ‘Low’ head – old mill sites with weirs and sluices

• ‘high’ head – fast flowing streams (usually upland).


Small scale hydro – how do they work?

• An intake

• A penstock pipe• A penstock pipe

• A powerhouse

• An outflow

• Cables to transmit elec.


Small scale hydro – permissions

• Planning

• An abstraction license• An abstraction license


case study 1 – the mill at Sonning

• Existing mill with race and wheel

• High energy use for cinema and attractions • High energy use for cinema and attractions during the day

• Low use and export at night



• 18.5kW Propeller and turbine fitted

• EA permissions granted, no abstraction • EA permissions granted, no abstraction license as ‘Millers rights’

• Project cost £54,000

• Generates about 153MW/year



2006 / 2007

Income £s Notes

Energy sales 2,280 76MW * £30 (3p / kW)

ROCs 5,967 153MW*39

LECS 612 153MW*4

Total income 8,859

Savings 4,408 76MW * £58 (5.8p kW)

Total 13,267



2008/ 2009

Income £s NotesIncome £s Notes

Energy sales 3,876 76MW * £51 (5.1p / kW)

ROCs 5,967 153MW*39

LECS 612 153MW*4

Total income 10,455

Savings 7,828 76MW * £103 (10.3p kW)

Total 18,283



• Seasonal variation – trash rack fills in the autumn and needs regular cleaning

• No good in floods as no head!

• Potential to expand and double the power!


Small scale hydro – further information

• www.britishhydro.org.uk

• www.flowline.co.uk• www.flowline.co.uk

• www.segen.co.uk/hydro

• www.hydrogeneration.co.uk

• www.environmentagency.org.uk

Renewable energy – biomass

• Focus on woodchip

Ancient Woodland

Other Woodland

Woodland Cover in SE England:

The ResourceWoodland Cover in South East England

County: Woodland Area

% Woodland Cover

Total Land Area

Ancient & semi-natural woodland

Plantations on ancient woodland sites

Total ancient woodland

(as per 2002 Inventory & inc. all woods > 0.1 ha)

Figures comprise all land which featured on the Provisional Ancient Woodland Inventory and in the 2,000 Inventory

Berkshire 18,308 14.5 125,880 3,600 1,770 5,370Berkshire 18,308 14.5 125,880 3,600 1,770 5,370

Buckinghamshire 17,573 9.4 187,675 4,885 3,910 8,795

Oxfordshire 18,235 7.0 260,595 5,075 2,650 7,725

Surrey 37,564 22.4 167,715 6,640 2,640 9,280

Hampshire 66,939 17.7 377,870 18,680 9,290 27,970

Isle of Wight 4,549 12.0 38,015 800 710 1,510

West Sussex 37,507 18.9 198,810 9,530 7,300 16,830

East Sussex 29,924 16.7 179,540 12,055 6,135 18,190

Kent 39,487 10.6 373,500 18,780 8,280 27,060

TOTALS: 270,084 14.0 1,909,600 80,045 42,685 122,730

What might this provide?

• Conservatively all woodland in SEE is growing at, at least, 4m 3 per ha per year = > 1,000,000m 3

• Of this perhaps 25% may be readily available for the wood fuel market = 200,000 dry (30% mc) tonnes = 70 million litres of oil tonnes = 70 million litres of oil

• Could be much more but is price dependent

Fuel costs

per kWh

Value of Coppice used for Fuel15 year old sweet chestnut yields 70-80 tonnes/acre S tanding Value

75 tonnes/acre (180t / ha)If you can sell worth £100-200 say £150 £150.00

Sell as fuel 60t @ £50 / t £3,000

Cost of producing woodchip

For woodchip - 1 acre felling £10 / t - £750 £750Chipping £10 / t £600Delivery £10 / t £600Sundries £5 / t £300

£2,250 £750.00£2,250 £750.00

NB 75 t green @ 50% moisture content air seasoned to reduce MC to 30%Weight reduces to 60 tonnes

1t woodchip@30%mc is approx equal to 400 litres of heating oil

60 t is approx' 24,000 litres

Woodchip can reduce heating costsIncrease income for woodland ownerImprove Woodland management - grants etc

Sell the best chip the rest!

5,000kg

Fossil CO 24,140kg

Fossil CO 2

90kg

Fossil CO 2

Carbon Dioxide Emissions From A Single Family Home

Using 18,000kw hours per year

Oil Gas Wood

HOW?Do you get from the woodland to the boiler?

Medium Scale Heat

Medium Scale Heat

Case Study

Conversion of farm buildings to offices with communal woodchip heating with communal woodchip heating

system

Worten Farm Office Conversion 3 Units – gross internal area 3,200 sq ft

Oil Woodchip

Capital Costs £7,500 £26,000

Annual Fuel Cost

£2,150 £600

� Additional Cost of Woodchip System £18,500

� Saving £1,500 per annum

� 12 years to recoup additional cost at current oil price

Annual Fuel Price Comparison

1500

2000

2500

3000

Oil

0

500

1000

1500

Budget Actual

OilWoodchip

Budget oil costs based on 30p/litre. Actual cost 48p/litre

Woodchip costs based on £50 per tonne

Renewable Energy - CHP

Combined Heat and Power

Renewable Energy - CHP

Combined Heat and Power – Trial site

• Requires 2.5 tonnes of biomass a day –forestry waste, straw, woodchip, miscanthusetc.

• 100kWh of electricity through a micro air turbine

• 200kWh of hot water

• Cost approx £300,000

Renewable Energy – Biogas

Biogas – Anaerobic digestions -background

• A natural process where bacteria breakdown organic matter in an environment with little or no oxygenoxygen

• Methane is produced (plus about 40% CO2)

• Methane is burnt in an engine to produce energy and hot water

• Usually large scale collaborative projects

• A 500Kw plant would cost in excess of £1,000,000


Biogas – Anaerobic digestion

CHPmanure

digester

Gas storage

Digestate storage

Agricultural residues

Imported organics pasteurisation


Biogas – Anaerobic digestions –background


Case study 2 – 500kWh plant on dairy farm

• 4 farmer Co – op

• 1.5 ha site (planning a big issue!)• 1.5 ha site (planning a big issue!)

• Plan to digest 20,000m3 of manure and 7,000 m3 of maize

• Expected production 4,000,000kW / year

• Plus 2,000,000kW hot water per year

• Long term plan to move from maize to food ‘waste’

Income MWh / year rate Total

Electricity sales 4,000 45 180,000

Hot water sales 2,000 0 5,000

digestate sales 0 0 0

ROCs 4,000 80 320,000

LECs 4,000 4.4 17,600

(gate fees) 0 0 0

Total 522,600

Expenditure

maize 300ha £400 / ha 120,000.00

land rental 300ha £150 45,000.00

cereal -

slurry / manure -

labour 1.00 50,000.00

management costs 10% 5,000.00

water 12,000.00 water 12,000.00

electricity 12,000.00

fuel 4,000.00

spreading digestant 4,000.00

annual maintanence 16,000.00

maintenance contract -

ROCS mmt. Charges 2,000.00

electricity charges -

fees / charges (legal) 10,000.00

insurance 5,000.00

sundry 5,000.00

accountancy fees 3,000.00

depreciation 157,333.00

interest 88,114.00

Total 538,447.00

Net profit / loss 15,847.00

Consider…

What are your Efficiencies

What

Heat

£

energy requirements

Efficienciesfirst

resources are available

Heat and power

Power

Paul [email protected] 333482101444 232822

Technology

Introduction to Farm Renewables - Paul Holmes-Ling (Laurence Gould Partnership)