Heating costs

[Ernie]

In early February I paid the three month combined gas/electric heating bill covering |November/December/January. The bill was over £1000 less the couple of hundred quid + paid by HM government. I actually forked out just over £800. I expect the next three monthly bill to be high again but not quite as high. My greenhouse heater is a Bio green Pheonix set at 5 degrees using a Bio green thermostat. I am not pleading poverty by any means nor looking for sympathy but at my age and financial commitments towards helping my two sons and grandsons I have been discussing the cost with my wife and there is a question mark as to to whether or not we keep the greenhouse going next winter if the current costs of energy are going to be the same. We are both in our late 70's and Elaine is recovering from cancer and I have health issues so we need warmth. I can see a problem arising if I decide to sell the collection, if there's many more folk in a similar position it becomes a buyers market place. Almost all of the collection cannot be kept below 4-5 degrees. The tender plants like Adeniums are kept in the house during winter.
Just wondering if any one else has had to think about the future and what to to do with their collections.

[Tina]

I would be disappointed with my grown up sons if i had to supplement their income, I know you help grandson's at uni but giving up my hobby - no way.

[iann]

I only heat on the very coldest nights, just a handful most winters. Anything that can't stand the occasional drop to -5C or so, or perhaps -3C inside the hotbox in the greenhouse, comes inside for at least part of the winter. I can remember nearly emptying the greenhouse about ten years ago when temperatures went well below -10C.

Tonight looks like it will hit my electricity bill, though! The hotbox is dismantled and I've already put out a few plants from their indoor holiday. So I've just dragged in all the Conophytums and ilk from one of the cold frames, only to find that the forecast has changed from -5C to -2C Still, I might not need the heater after all

[Cidermanrolls]

I have four greenhouses, combined total around 370 sq.ft. Each has a 1kW electric fan heater, controlled by an external digital thermostat. Each is insulated with twin wall polycarbonate. The coldest is set to 1.5c and the warmest to 4.5c.
The electricity bill for our whole home over the last three months is £770.
Sounds a lot, but it covers the house, the greenhouses and my workshop which I regularly work from all day and which uses several electrically powered machines.
From the consumption charts I can easily spot the cold weeks of December, but there are few other spikes. My estimate is that the greenhouses have cost under a quarter of my total bill.
What I have done to reduce costs is to turn the thermostats down. All of the greenhouses are running colder than last year. I’ve brought a few sensitive plants indoors as a result.
I won’t be giving up my collection, I’d rather give up other luxuries first. But I might nudge the thermostats even lower, if I have to.

[Ernie]

I would be disappointed with my grown up sons if i had to supplement their income, I know you help grandson's at uni but giving up my hobby - no way.

As I have aged, and entered old age, I no longer see my self needs/desires as having any importance. I get enjoyment out of helping my family. If the collection needs to go so be albeit with much sadness, the collection I have was intended to see out my days however........ We will see.

[el48tel]

Percentage marginal improvement theory. Worked for the Olympic teams.
If you make small reductions in a large number of items, the overall effect is multiplicative rather than additive. The latest HM government ad is trying to encourage that.
Your GH plants might be forgiving if you reduce the temperature by 0.5C ..... similarly your main sitting area. Reduce the time the heat is on by 30minutes per day in total .... etc. It does have a mathematical basis. But the fallacy is to turn heating off totally for a large portion of the day. Again mathematically you can show that it takes more energy (and cost) to raise the temperature back from a lower temperature than to maintain it at a steady value.

[edds]

I'm planning a new greenhouse and am hoping to design it to run as a passive greenhouse with minimal heating (we will see how successfully after it has been built!). When I do need heat I am looking at the air to air heat pumps, after reading an article about a member using them for their greenhouse.

My main design plan is heavily insulating the north facing side of the greenhouse (with reflective surface to reflect as much light as possible) and having a large quantity of contained water to act as a heat sink. I am also planning that this greenhouse will only be frost free and filled with things that can cope with that.

Perhaps you could add better insulation on the north side and black water barrels on that side to help save the heat in the greenhouse? The other option is to move to species that definitely don't require the heating. My Opuntia fragilis collection are staying in the cold greenhouse tonight as some are from as far north as Vancouver Island!

[Cidermanrolls]

Again mathematically you can show that it takes more energy (and cost) to raise the temperature back from a lower temperature than to maintain it at a steady value.

Erm….no. That is a myth. Heat loss is proportional to the differential between the warm part and the cold part. The warmer the house, the more heat it takes to keep it warm.

[el48tel]

Again mathematically you can show that it takes more energy (and cost) to raise the temperature back from a lower temperature than to maintain it at a steady value.

Erm….no. That is a myth. Heat loss is proportional to the differential between the warm part and the cold part. The warmer the house, the more heat it takes to keep it warm.

We'll have to agree to differ on the mathematical interpretation of the statement you make on which we do both agree.

[Rayc11]

I recently invested in a couple of Smartplugs that can record power consumption for the 2 off 2Kw. heaters in my 22ft. x 8ft. Greenhouse. They are both controlled by a Biogreen electronic Temperature controller set to maintain a minimum temperature of 3°C. This month so far temperature has never dropped below 3.5°C. Power consumed so far this month is 44.77Kw. Unit cost 32.81p. per Kw gives a total cost for the 10 days of the Month of £19.25 (including the Standing Charge which for 10 days £4.57)