Looking under the bonnet 1 – Powis Castle

For the next few months we will be highlighting the environmental work of each of National Trust properties around Wales. The first of which is Powis castle.  I was there last Wed with Garry Sharples my colleague from up North West. In essence its a stunning castle, garden and nursery. It gets about a 100,000 visitors per annum and uses quite a bit of electricity and gas. The main challenge was the electricity use in the castle and  Nursery and to lower the gas use.  On Wed we had a walk and talk around the property and to tell you the truth I had forgotten how much work has gone on at the property since we started.

wonder why people come here? Gardens = Stunning

The highlights of the property include –

Energy generation –

  • A 10kw and 40kw PV array feeding the nursery and Lady violets tea room.
  • 27Kw ground source heat pump again for the nursery.
  • 5 air source heat pumps 0 shop, tea rooms, gardeners mess room
  • 25kw Passat log boiler system. For the workshop

Energy efficiency

  • Some new secondary glazing in the castle
  • Value and flange insulation in the boiler plant room
  • 800m2 of 270mm of roof insulation
  • Smart metering on the gas, electricity and water use


  • capillary feeding system on the terrace
  • sand bed arrangement water feeding the plants in the nursery
  • new borehole feeding the nursery. replacing a mains water system


  • Aerobin and Bioland food composters
  • large composting area with a reed bed taking the leachate

The Victorian nursery is now well served in terms of energy generation. heat pump, PV. Its also got a well sorted composting and reed bed system

Over all this property has an exemplary commercial nursery system and is set up well in terms of air source heat pumps. But whats left to do? – as one of the few natural gas heated properties in Wales it’s not top of the list for changing to a more renewable source. This is because we are targeting the oil use properties both on carbon but also cost wins. We have some work to do with the property in terms of adjusting the BMS system (this years summer and high relative humidity levels have shown room for improvement) . The holiday cottage on site needs some fettling but is part of the Wales holiday cottage energy efficiency work currently underway. The Gardeners are working on  moving the main terraces off mains water. We need to finalise the LED change over and look at further secondary glazing. The heating could one day could be replaced or supplemented by heat pump or biomass but that is quite a bit down the road.

Finally like all National Trust properties in Wales the team here is looking at how to make access easier and lower the carbon emissions from our visitors who drive to the property. But do this in a way which saves money, carbon and hopefully increases the ‘fun’ element. Watch this space.. We have some ideas but suggestions on a post card.

Increasing fuel costs, carbon impact. Let work to make it better and easier for our visitors

This entry was posted in Heat pump, PV, Waste, Water and tagged , , , , , , , , , , , , , . Bookmark the permalink.

One Response to Looking under the bonnet 1 – Powis Castle

  1. Pingback: Looking under the bonnet 1 – Powis Castle | National Trust Green Gardening

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s