Portmeirion 2.2MW District Heating Installation Mike Collison,
Portmeirion is a popular Italian architecture, tourist village in North Wales, once the setting for the iconic TV series The Prisoner. Portmeirion Ltd spent 2 years researching large scale district heating projects, looking into the feasibility and financial practicalities of installing one to heat the entire village.
The location featured a range of properties, from small flats, a castle and a hotel, which were heated by various heat sources such as LPG, oil and electricity. The goal of the project was to transfer as many of the properties on the site as possible onto the district heating scheme and away from expensive fossil fuels.
A total of 29 buildings were selected to be part of the district heating scheme, almost 90% of all building in Portmeirion Village. We took part in a series of tender s for this project. Due to range and variety of tenders submitted, external consultant s were appointed to finalise the requirements. In October 2015 we won the tender and work began. We quickly realised that the project had many obstacles that we would need to tackle throughout the installation
The first obstacle we encountered was the language barrier or inability to siarad cymraeg. We wanted to ensure the project supported the local community in North Wales as well as Portmeirion Village itself so 100% of purchases throughout the project were from Wales, including the wood chip that will fuel the biomass boilers.
One obstacle we faced was the weather This project was to be carried out between November and March the shortest and wettest part of the year. In the beginning things were easy with beautiful weather. 3.5 kilometres of trenching was eventually excavated, or 2 miles in old money.
The REHAU pipe is laid in the excavated trenches with 6 inches of sand all the way around, to ensure minimum heat loss.
The waterfall added to the scenic beauty. All these joins must be kept clean, easy enough until the rain started
and the rain continued throughout the excavation.
This meant that our excavations and pipe laying teams had to work late into the night and early hours of the morning to make sure the project was kept on schedule. Always fill a trench, or the rain will wash the sand to the bottom and you will spend a lot of time, hand digging to put it right. Some unfortunate members of the team even suffered with trench foot
The next obstacle we faced was the pond There was a beautiful pond in the middle of the village, plans were made to go around this area, but after much toing and froing - several of the 22 pipe run changes were to get round this obstacle..
It was decided the only way to go was through it! The pond was drained and dug out, we then created a massive blanket of sand and pipe wrapped in heavy duty sheeting and then covered again.
The pond was then put back together again.
Another obstacle we faced was working around Portmeirion s visitors and opening times. All work would have to be scheduled around the paying guests, who were either, day visitors or staying in one of the properties/castle/hotel. Work in the village could only take place between 10am and 3.30pm, and if a customer complained or was disturbed, work was suspended until they were pacified or upgraded to different accommodation.
Whist overcoming these various obstacles we maintained open and detailed communication with the client. All of us had our patience tested when the client changed the pipe runs some 22 times every time this happened a total recalculation of pipe sizing, flow rates and pump sizing had to take place. With so many branches and tee off s the logistics were interesting to say the least.
Daily/Weekly/Monthly meetings kept everyone informed of schedules and progress. The plan was constantly updated to show progress.
The logistics of this project also proved to be a challenge The project was particularly challenging because of the 50m height difference between the Castle at the top of the village and the hotel at the bottom. With different pipe runs, running uphill and downhill, particular care had to be taken when considering the working pressures of the system, whilst trying to achieve the 85/65 C flow and return temperatures set out in the specification.
One major logistical challenge was the castle, situated at the top of the village. This was one of the hardest entries to the properties at Portmeirion as the plant room was 15m above the ground in the middle of the roof. In addition to this the pipe approach to the castle was difficult, we had to make sure any pipework was hidden from view.
We transferred from REHAU into Stainless Steel above ground and fabricated pipe fixings underneath the roof line of the castle. We followed this line up the castle wall and cored through into the plant room wall. We then had to integrate into the existing castle heating system, whilst the castle was occupied.
Next was the hotel, which Portmeirion were particularly concerned with, as there was to be no backup within the building once we had disconnected the existing oil boiler. The run to the hotel was through shale, rock and rock rock. The run to the hotel had to be dug and filled between Monday at 12pm and Friday at 3pm, things were a little fraught at times.
There were multiple obstacles and services to overcome.
Having installed the REHAU pipework to the hotel the next challenge was the hotel change over. It needed to be completely stripped out and connected to the district heating main within a 7-day period. After the 7 th day a wedding reception was booked in!
Having removed 2000 litres of hot water storage we had to ensure that the system was able to provide a constant supply of hot water. The engineers worked all night to ensure the system was turned on at 5am ready for the guests.
The multitude of various integrations meant we had to think outside the box when it came to connecting each property to the district heating system. Here the REHAU pipe comes out of the ground, goes into 35mm Xpress pipework. It then runs up inside the exposed brickwork, which is then repaired to ensure nothing is visible.
During the entire project the energy centre took shape. We had hoped it would be ready by the start of the project, but in the end it was completed at the same time as the rest of the project. Once the energy centre was half finished we were able to begin installing the plant room.
Two 17,500 litre buffer tanks arrived ready to be installed in the new Energy Centre. Getting them off the lorry and into the correct position is a delicate procedure.
The Energy Centre consisted of 2 x 499kW Froling TM biomass boilers, 2 x 620kW Hoval oil boilers, 2 x 18,000 litre thermal stores, filtration unit, Trend BMS, Grundfos pump sets & an expansion system.
The boilers were delivered in bits, which were put together piece by piece inside the energy centre.
Engineers from the chosen suppliers assisted in the piecing together the boilers. The internal plant room pipework was all welded on site.
Froling biomass boiler & buffer tanks complete.
There was extensive pipework to install and clad inside the plant rooms and to connect up each of the 28 properties
The hotel plant room took over a week to insulate alone. Even the tricky pipe runs had to be insulated.
Inside and out The external pipes needed extra weather proof cladding to protect them. Where this pipework was visible, it was boxed in.
The Energy Centre was just high enough to take an artic with a walking floor to deliver the wood chip. Portmeirion expect to need an artic load each week.
Completed cascade 1MW biomass boiler system.
Completed 2x 600kw Hoval oil boilers and management system.
The BMS system controls the link between the biomass and oil boilers. This system is linked to our offices and the service engineer. And just when you think you have finished, the project manager tells you one of the boilers has a leak on it
Portmeirion Ltd have invested over 1.5 million on this district heating scheme to provide the village with heat and hot water. Portmeirion village will benefit greatly from using a more efficient system, saving money on energy, earning through the Renewable Heat Incentive scheme and lowering their carbon footprint, thereby future proofing the beautiful village for many years to come. In the words of architect Clough Williams- Ellis, we should cherish the past, adorn the present and construct for the future and that is certainly what we have done with this project. - Robin Llywelyn, Managing Director, Portmeirion Ltd
Thank you for listening. Contact Us: www.espenergy.co.uk info@espenergy.co.uk 01743 718003