Waste as Energy
This essay examines the nature of energy from waste as a fuel source.
It establishes the problems, amount of waste produced nationally, the waste sources, the amount of landfill available, the potential energy from waste, the potential waste amount per authority, the potential energy available, the potential revenue from the energy and the stages of a waste to energy system.
Conclusions are then drawn from the data.
The Problems
The UK is dependent on fossil fuel use to the level of 76% of its generating capacity.
Source: CIA World Factbook 2015
Allowing for the reduction in generating capacity to 9.2% by 2050 there is a shortfall in UK energy production compared to population level consumption.
This would mean that the population would need 395.6 billion kWh but only get 32.4 billion kWh.
This is a shortfall in energy of 363.2 billion kWh.
Alternative fuel supplies are therefore needed.
The Data
Amount of Waste Produced
The UK produced 57,000,000 tons of landfill grade waste in 2010
Source: Independent. UK warned it will run out of landfill sites in eight years Thursday 08 July 2010
Waste Sources
These are the UK waste sectors in order of the volume of waste produced from them.
Only part of the waste was transferred to landfill.
Construction 105,560,290 tonnes
Commercial and industrial 43,342,791 tonnes
Households 28,948,507 tonnes
Mining and quarrying 23,091,832 tonnes
Secondary, sewage and other 2,110,195 tonnes
Total 203,055,625 tonnes
Source: 2010 figures from Energy from Waste a Guide to the debate February 2014. DEFRA
Amount of Landfill Volume available.
The UK has until recently used landfill to dispose of its waste.
Landfill is however no longer a viable disposal option due to EU legislation and UN Agreements
Even of the legislative control had not been applied then the UK would still be running out of landfill volume. The UK had 650,000,000 cubic metres of landfill volume available for use in 2010.
This allowed for; in 2010 waste production levels; amounts to 11 years of waste disposal volume up to 2020.
Energy potential from Waste.
It has been estimated that 450-600kWh are potentially available per tonne using a steam turbine generator in a waste to energy facility.
Source: http://www.building.co.uk/cost-model-energy-from-waste/3162156.article
Potential waste amount per UK Authority
There are approx. 433 authorities in the UK.
For the total UK waste production of 57,000,000 tonnes of potential waste that can be converted into energy this amounts to 57,000,000 tonnes over 433 UK authorities Approx. 131,640 tonnes per UK authority
Potential Energy from Waste
At 450-600 kWh per tonne potential energy.
= 600 x 57,000,000 tonnes.
= 34,200,000,000 kWh potential energy.
= 34,200,000,000 kWh / 433 authorities
= 78,983,833 kwh potential energy per UK authority. 17,552 homes at 4500 kWh / year
= at 10.435p kWh unit price (First Utility)
= at £51.47 Annual standing charge (First Utility), 0.14p per day over a year.
= Total possible cost for electricity per day of 11p kwh
Source: http://www.ukpower.co.uk/home_energy/tariffs-per-unit-kwh
Potential Revenue
For 78,983,833 kWh per UK authority potential energy at 11p per kWh value.
= £8,688,222 potential revenue into the waste to energy system per authority in the UK.
The Stages of a Waste to Energy System
Stage 1 Collection
Allowing 1 refuse vehicle to carry 11 tonnes of material waste.
Source: http://news.bbc.co.uk/1/hi/england/humber/4563878.stm
Allowing 433 local authorities with 11 vehicles each
Source: http://en.wikipedia.org/wiki/Political_make-up_of_local_councils_in_the_United_Kingdom
= approx. 5000 refuse vehicles in the UK
Allowing for a capital cost per refuse vehicle of approx. £130,000.
Source: http://news.bbc.co.uk/1/hi/england/humber/4563878.stm
= 5,000 x £130,000
= £650,000,000 refuse vehicle cost for the UK
Allowing a running and maintenance and crew cost percentage per vehicle of 10%
= £715,000,000 for refuse vehicle cost in UK
= £715,000,000 / 433 authorities
= £1,651,270 cost for refuse collection per authority in UK per year.
The Stages of a Waste to Energy System
Stage 2 Pre-Treatment Plants
Bulking facility. Bunker storage of waste materials.
£50,000 to £100,000 capital cost.
Area is reclaimed from existing waste sites.
Efficiency 100%
Source: http://www.nlwa.gov.uk/docs/waste-recycling-guides/yourguidetowastedisposal.pdf
Materials Reclamation Facility.
£5,000,000 to £10,000,000 capital cost.
Area: 1 to 2 Hectares.
Construction time 1 year.
Efficiency 95 to100%
Source: http://www.nlwa.gov.uk/docs/waste-recycling-guides/yourguidetowastedisposal.pdf
Reuse and Recycling Centres
£1,000,000 to £2,000,000 capital cost.
Area: 1 to 2 Hectares.
Construction time 1 year.
Efficiency. 100%
Source: http://www.nlwa.gov.uk/docs/waste-recycling-guides/yourguidetowastedisposal.pdf
Composting Centres.
£500,000 to £6,000,000 capital cost.
Area: 1 to 2 Hectares.
Construction time 3 to 6 months.
Efficiency. 100%.
Source: http://www.nlwa.gov.uk/docs/waste-recycling-guides/yourguidetowastedisposal.pdf
Anerobic Digester
Biodegradable waste broken down in a digester container and gases removed.
£3,000,000 to £4,000,000 capital cost.
Area: 0.05 to 1 Hectares.
Construction time 1 year.
Efficiency. 100%
Source: http://www.nlwa.gov.uk/docs/waste-recycling-guides/yourguidetowastedisposal.pdf
The Stages of a Waste to Energy System
Stage 3 Treatment of Waste from Stage 2
Mechanical Biological Treatment (MBT) Mechanical sorting followed by biological treatment.
Treatment volume of 50,000 to 180,000 tonnes per year.
£15,000,000 to £20,000,000 capital cost.
Area: 1 to 4 Hectares.
Source: http://www.nlwa.gov.uk/docs/waste-recycling-guides/yourguidetowastedisposal.pdf
Or
Mechanical Heat Treatment (MHT)
Mechanical sort then heat treatment to reduce moisture content.
Treatment volume of 50,000 to 180,000 tonnes per year.
£15,000,000 to £20,000,000 capital cost.
Area: 1 to 4 Hectares.
Source: http://www.nlwa.gov.uk/docs/waste-recycling-guides/yourguidetowastedisposal.pdf
The Stages of a Waste to Energy System
Stage 4 Energy from Waste
Types
Incineration
Anaerobic digestion (from mixed residual waste, often as part of an MBT process).
Source: Energy from Waste a Guide to the debate February 2014. DEFRA
Source: Energy from Waste a Guide to the debate February 2014. DEFRA
Incineration
£25,000,000 capital cost
For a 23,000 tonne per year.
Area: 1 Hectare
Source: http://www.nlwa.gov.uk/docs/waste-recycling-guides/yourguidetowastedisposal.pdf
This gives a square metre cost of £2500/ m2
Or
£70,000,000 capital cost.
For a 585,000 tonne per year.
Area: 5 Hectares.
Efficiency: 27% of waste turned into energy.
Source: http://www.nlwa.gov.uk/docs/waste-recycling-guides/yourguidetowastedisposal.pdf
This gives a square metre cost of £1400/m2
Anaerobic digestion
Advanced Thermal Technologies (ETT)
Types
Gasification (including plasma gasification);
Pyrolysis;
Source: http://www.nlwa.gov.uk/docs/waste-recycling-guides/yourguidetowastedisposal.pdf
Source: Energy from Waste a Guide to the debate February 2014. DEFRA
£9,000,000 to £50,000,000 capital cost.
For a 585,000 tonne per year.
Area: 0.5 to 3 Hectares.
This gives a square metre cost of £1400/m2
Efficiency: 30% of waste turned into energy.
Source: http://www.nlwa.gov.uk/docs/waste-recycling-guides/yourguidetowastedisposal.pdf
Conclusions
Combined Costs
The combined costs for a typical local authority waste to energy system in the UK
= 131,640 tonnes of waste per UK authority
= 78,983,833 kwh per UK authority potential energy.
= 10.435p Kwh unit price (First Utility)
= £51.47 Annual standing charge (First Utility)
= 0.14p per day over a year.
= Total possible cost for electricity per day
= approx.. 11p kwh
Source: http://www.ukpower.co.uk/home_energy/tariffs-per-unit-kwh
= 78,983,833 kwh per UK authority potential energy. 17,552 homes at 4500 kWh / year
= £8,688,222 potential revenue into the waste to energy system per authority in UK
Capital Costs
Stage 1 costs
= £1,651,270 cost for refuse collection per authority in UK
Stage 2 costs
= £22,100,000 cost for refuse Pre-Treatment Plants per authority in UK
Stage 3 costs
= £20,000,000 cost for Treatment of Stage 2 remaining waste per authority in UK
Stage 4 costs
= £70,000,000 cost for Energy from waste per authority in UK
Total costs
= £113,751,270 cost for waste system per authority in UK. The cost of 455, £250,000, homes.
Land Loss
The land used for a waste to energy facility amounts to approx. 20 Hectares. Enough for 900 homes.
Source: Land Use Change Statistics (England) 2009 - provisional estimates (May 2010)
Allow £18,000 for equivalent pasture land per hectare, land value = £ 360,000
Source: http://www.dairyco.org.uk/market-information/farm-expenses/land-prices/land-prices-rics/
Payback Time
£113,751,270 + £360,000 / £8,688,222
This allows for a payback time of 13 years
Time
The total time to complete the construction of a waste to energy facility is approx.4 years
Issues
The capital costs of a waste to energy system are very high for a local authority to add to council tax levels and so they would need to be cost proven by competitive tenders to Contractors, Subcontractors, Suppliers and Manufacturers.
The local authority may decide to share the facilities and so increase the size of the plant to make it more cost effective.
The land lost and its commercial value will not be recovered for the lifetime of any of the plants in operation.
The construction time requires another waste disposal location be obtained at cost for 4 years.
The potential revenue from the electricity generated compared to the total cost suggests a payback time for the waste to energy system of 13 years.
This gives a total time for investment to cover of approx. 20 years.
The waste to energy system can provide enough energy to power approx. 17,000 homes local to it.
The cost of the waste to energy system is the same as approx. 455, £250,000 homes.
Waste is an inevitable output of a society. The UK society is increasing in population and so waste will increase. With landfill being made illegal and landfill for toxic waste running out alternative options to deal with waste are needed.
The overall costs, timescales, land lost and payback level therefore suggest that a waste to energy system is a viable energy generation system.
Ian K Whittaker
Websites:
https://sites.google.com/site/architecturearticles
Email: iankwhittaker@gmail.com
09/04/2015
14/10/2020
1518 words over 5 pages