Mark Summerfield - Burnley College
An early start on the final day of the trip saw us visiting the original district heating and gas fired energy generation plant for Zella Mehlis. The plant is currently on standby, and is now be used as a back-up in case of shutdown of the adjacent recycling/incinerator facility which has been supplying heat and energy for the town since 2007. The plant is used to supply heat and energy when the recycling plant is shut down for maintenance, and in times of peak demand such as the depths of winter.
The district heating scheme supplies public buildings, schools, hotels, etc. and heating for 150,000 people, with a maximum output of 30MW of heat and 13.5MW of electricity, using up to 1400 m3 of gas per hour. There are 35km of pipework installed and the system has a 5000m3 of water storage. The systems pumps up to 800 m3 per hour at a temperature of 125oC. The pressure leavers the plant at 10 bar and rises to 20-22 bar in the town. There is a further back up facility whereby the system can also run on Heating oil.
The electricity is generated at 10kV and distributed through the grid via a 30kV star/delta and delta/delta transformer system.
This visit completed the energy provision for the area and the fact that the gas turbines are not used except as standby shows that it is possible to provide energy for the area purely using renewable technologies. The combination of Waste incineration, PV farms and local PV installations, hydro and solar thermal provides the community and industry with all their energy needs.
Following a debriefing session back at BCS the group thanked Herr Gerlach and the team from BCS and Dirk Bischoff from Embrace for their hospitality, and generosity during the exchange visit. All delegates had gained from the experience, and felt the trip had been very worthwhile, with examples of best practice being taken back to the UK.
Muhammad Yousuf - Dan & Adam
It has been a thoroughly engrossing week. At least 9 out of 10 for the usefulness of the week in terms of knowledge exchange, connections, friendships and use of time.
There have been many standout points from the week;
- These include the generous nature of the hosts in terms of time and commitment to the visit. A striking feature has been the genuine emphasis - from all involved in the week - on involving youngsters in the renewables sector, informing youngsters, training youngsters, inspiring youngsters.
- Additionally also from an integrity perspective, it is clear that all the politicians and business leaders met have a genuine personal interest and desire to promote the renewables industry. This leadership is in contrast to the UK where renewables is clearly a political football in many parts of the UK.
- The visit on the last day to the district heating system in Zeller Mehlis and its capability to deliver sizeable capacity of heat and electricity > 100 MW when fully operational (storage also released) when required showed the seriousness of adopting as much renewables sourcing for heat and power as possible. It was not even necessary to turn it on fully due to the recycling plant incinerator feeding into the system.
All in all, well worth the visit.
Rowan Langley - Funky Renewables
This day had a very early start, and began with a visit to the gas fired heat and electricity generating station on the boundary between Zeller-Mehlis and Stuhl. Built in the 1960s and re-fitted between 1995 and 1998 the installation generates around 13 MW of electrical power which is connected to the local distribution networrk at 10 and 30 KV, and around 30 Kilowatts of heat for District heating in Stuhl and parts of Zelle-Mehlis close to the boundary with Stuhl. Superheated water, at temperatures between 95 and 130C is piped under pressure (between 5 and 10 bar) to calorifiers in public buildings and some of the former social housing blocks of flats where heat ois abstracted via heat metres.
Since 2007 however, the majority of the local and heat generation has been provided by the recycling station and incinerator complex adjacent to the Autobahn exit for Stuhl and Zella-Mehlis, which serves the South Thuringen region. The facility feeds power and heat to the generating station, which houses the electrical and heat control room for the system. One of the two 18 KW gas boilers runs boosting the heat input from the incineration plant ready for distribution, and the gas turbines are kept in standby to deal with the winter periods of very high heat demand.
These installation demonstrate a feature of utility provision not found historically in the UK, which has been a retention of local generating facilities. The UK electricity undertakings were historically charged with providing electrical energy at lowest cost, leading to power stations of large size located close to coal reserves, and the efficiency requirements for low cost electricity production resulted in heat being emitted at too low a temperature to be useful for district heating and the station to remote to make heat mains workable.
Our final session was hosted back at the BCS centre, consisting of a tour of both training facilities and the small injection moulding company spun off from the BCS utilising staff who would othersie have faced redundancy, making moulds and moulded items to order and for profit, and able to draw on the expertise within the BCS and also be able to give some training placement opportunities.
Claire Chapman - Scottish Water
Today was our last day of site visits, and we started early with a trip to the local Stadwerke (power station). It is gas fired and is now primarily used as a backup to the local incinerator (commissioned in 2007) which can produce 30 MW of heat and 13 MW of electricity. As landfill is now banned in Germany this plant is always run in preference to any other.
We finished the morning with a visit to the Building Center SudThuringen (BCS) Training College, going into some of their training workshops, and admiring their impressive arrays of metal working equipment. And then it was times for goodbyes, and thank yous for an interesting week of site visits. Herr Gerlach (Director of BCS and host coordinator of our trip) left us by saying that the key focus is to educate the youth; making sure they realise the need to develop Renewables. From what we have seen this week, I think Germany has led the way in this, and can be congratulated on such a focus and drive on Renewable awareness.
Damien Tow - Brighton Energy Co-op
