District heating: learning the hard way. Neil James Environmental Research Institute, UHI

Transcription

1 District heating: learning the hard way Neil James Environmental Research Institute, UHI

2 Anaerobic digestion for waste management Neil James Environmental Research Institute, UHI

3 Scotland Case Studies

4 Scotland Case Studies

5 Scotland Case Studies 2 1

6 Scotland Case Studies Wick district heating scheme 2. Creed integrated waste management facility

7 Scotland Case Studies Wick district heating scheme 2. Creed integrated waste management facility

8 Wick Located in the county of Caithness in the Highlands of Scotland Originally designed as a new major fishing town Current population of ~7 000 (2010 estimate)

9 Percentage households in national lowest income quartile Percentage households in fuel poverty 0 to 10% 10 to 20% 20 to 30% 30 to 40% 40 to 50% 22 to 30% 31 to 34% 35 to 30% 40 to 57% Scottish Government Scottish House Condition Survey (2012)

10 Wick District Heating Scheme Objective: To provide lower fuel poverty through the provision of a renewable fuel source

11 Wick District Heating Scheme Project set up in 2002 with the aimed of providing heat and hot water to 500 homes in Wick using a renewable source of energy To expand to up to 1000 homes and generate income from the sale of electricity to the national grid Locally based council officers propose Community Energy Initiative in August 2002 Project approved in 2004 Caithness Heat and Power Limited (CHaP) established, an arms-length community-owned enterprise CHaP founder members are Inverhouse Distillers from Wick Distillery, Pulteneytown Peoples Project, and The Highland Council

12 Wick District Heating Scheme February 2006 Caithness Heat and Power open day March 2006 Pipe work starts to be installed August 2006 System switched on using excess heat from local distillery to supply 170 houses Temporary measure until new innovative biomass gasification plant is installed The new unit will allow the sale of electricity to the grid will provide further revenue for expansion

13 Gasification system Biomass fuel is harvested, sized and dried. Material may be waste wood, sawmill wastes, willow etc. Fuel fed into gasifier and converted into fuel gas (syngas) Fuel gas combusted in engine Electricty Gas

14 Wick District Heating Scheme Homes previously heated using either electric storage, coal, gas, or oil Council house tenants had the system installed free of charge Private home owners could pay to have the system installed Prices to customers set, with rises not exceed the retail price index ~ 277 per annum for 3 bedroom house

15 Wick District Heating Scheme February 2007 to March MWe Gasification engine and plant installed May 2007 Heating system spread out across Wick July 2007 Heating system reaches Caithness General Hospital Problems with the new gasification system means relying on an oil-fired boiler

16 Wick District Heating Scheme requests to council for funding: capital funding, bridging finance and emergency finance In 2008 the council took over ownership of the company owing to financial and technical difficulties Council aimed to improve governance and financial stewardship, maintain heat and hot water to the 247 houses connected to the system using a temporary oil-fired boiler, and seek a longer term solution

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18 Wick District Heating Scheme Caithness Heat and Power Scheme came to an end on 16 th Dec 2011 The net cost of CHaP scheme to the Highland Council was million (Highland Council housing director) Highland Council bought trade and assets for nominal value of 1 (December 2011). This was the end of CHaP. Equipment belonging to CHaP sold at auction to Ignis Biomass

19 Wick District Heating Scheme Fundamental failings in the way the project was initialised and authorised, and in risk management Ultimately the project failed because the company procured experimental and high risk gasification technology which could not be commissioned successfully. In awarding the contract, the CHaP Board decided to procure a system which had no clear history of success elsewhere

20 Wick District Heating Scheme Ignis Biomass took over operation in April 2012 Ignis installed a new 3.5MW steam boiler running on wood chips. Established technology from established company 2.5 million invested in the community heating project 9 out of 10 replying tenants signed up to the Ignis Biomass district heating scheme Supplying ~200 houses (246 on CHaP system), can connect a further 1000

21 Wick District Heating Scheme Using wood chip fuel, sourced locally Tenants offered fixed weekly tariff or a meter Providing renewable energy (steam) to Pulteney Distillery, previously running on heavy fuel oil Wick District Heating scheme now supplies the Wick Assembly Rooms (public performance venue), previously heated with an oil-fired boiler Plans to supply heat to Caithness General Hospital and new Wick High School

22 Wick District Heating Scheme

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24 Wick District Heating Scheme Reduction in greenhouse gas emissions of customers (up to 90%) tonnes CO 2 per year less than under CHaP scheme Cost of heat 33% less that cheapest alternative Saving ~ 200 per year

25 Scotland Case Studies Wick district heating scheme 2. Creed integrated waste management facility

26 Creed Waste Management Facility Located in Creed, near Stornoway, in the Western Isles (Eilean Siar) of Scotland Population of Western Isles ~ Lewis and Harris ~ Stornoway ~ miles end to end 55 miles from mainland Scotland

27 Creed Waste Management Facility Objective: To minimise the amount of waste going to landfill

28 Creed Waste Management Facility Aims to meet, and exceed, targets for recycling and landfill diversion set by the Scottish Government 50% of household waste needs to be recycled or composted by 2013 Recycling 70% of all Scotland s waste and only 5% of remaining waste ending up in landfill by 2025 Contribute to Scotland's requirements of the European Landfill Directive

29 Creed Waste Management Facility High proportion of customers spread across remote and rural communities Disposal of waste a financial and logistical challenge for local authorities Remoteness from mainland Cost of transport Efficient and environmentally-sound collection difficult Seasonal increases in waste generation Logistics of waste collection, recycling, treatment and disposal are more difficult that for other parts of Scotland

30 Tax per tonne ( ) Landfill Tax Escalator Cost of waste going to landfill currently 72 per tonne Cost to Western Isles council per year (2011)

31 Creed Waste Management Facility Organic-rich fraction of household waste In-vessel composting Dry recycling Glass, can separation and baling, plastics baling Treatment of source-separated biowaste Paper, garden and kitchen waste Anaerobic digestion

32 Anaerobic digestion plant Treatment of source-separated biowaste Paper, garden and kitchen waste Owned and operated by the Western Isles Council (Comhairle nan Eilean Siar) Cost of AD part of waste facility ~ 7.5 million A contract awarded following tender, to Earth Tech build two integrated waste management facilities Commissioning of the facility began in Oct 2006, and the biogas engine in May 2007

33 Anaerobic digestion plant Paper, garden and kitchen waste from the northern isles (Lewis & Harris) and southern isles (the Uists, Benbencula, and Barra) Residual waste (black bags) only from northern isles First plant in the UK to incorporate anaerobic digestion of source-separated biowaste on a commercial scale. Uses Linde dry-digestion technology

34 Dry digestion plant (Linde)

35 Anaerobic digestion plant Over 3000 tonne domestic organic waste collected per year, around 1800 tonnes used for waste energy Solid digestate is matured to produce highquality compost for local use Saves up to 400 tonnes CO 2 emissions per year

36 Anaerobic digestion plant Biogas produced is used to generate electrical power which is metered and sold to the local network (2 million kwh per year) Annual production: 438MWh electricity, 684MWh thermal energy Also received benefit of Renewable Obligation Certificates (ROCs) value of the energy produced

37 Creed Waste Management Facility Biogas plant operating at about one-third of it s full design capacity Overestimated quantity of organic material in, and recoverable from waste of domestic users Significant technical difficulties with the in-vessel composters have prevented their effective use since December 2007 Potential for greater generation of electricity

38 Creed Waste Management Facility Residual waste stream had been diverted to landfill directly without undergoing processing Ongoing programme of public education to promote source segregation of organic material and to maximise organic material recovery

39 Creed Waste Management Facility Manage as much waste on the islands as possible Minimising transport costs Reducing CO 2 emissions Meet the required Scottish recycling and diversion targets Producer of renewable electricity Producer of high and low grade compost materials, for agricultural and restoration benefit Potential to treat fish waste in the future, and that of other industries

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