Heat Pump Y/N:

I discounted heat pumps very quickly from my own list - not because I had a radiator system, not because of the cost of over sizing the radiators or putting in under floor pipes. No, the only reason was that heat pumps use electricity, and a lot of it. And as we already know how inefficient the electricity that reaches our homes is, having lost appx 70% of it through poor generation and poor distribution, I did not want to add to that scenario by requesting more of this 'dirty' source. Recalling the Kwh required for average use, there is no way I would be able to generate that amount of continuous wattage from my own wind/solar electricity project to be able to run the heat pump. I could hardly call this an experiment in renewable technologies if I went down this road and stared to use more GRID electricity, could I?

It is interesting that SEI themselves, in their Frequently Asked Questions (FAQ) about heat pumps- pose the following question: 'why support heat pumps in grant aid when they use electricity?'. Their answer is that heat pumps when correctly designed could reduce the running costs by one third compared to oil, thus the overall Co2 emissions are reduced. Which is another way of saving, "we know the source is inefficient but if you use less of it we will still give you a grant!" Hmmm. Now, wouldn't it have made much more sense to offer people the grant who are willing to locally generate their own green electricity from wind/solar solutions? And I have been hearing feedback that suggests only 50% of people are happy that their installed heat pump is actually reducing their energy bills. In other words, all they have done is swap from one inefficient fuel source to another. And remember you remain tied into the oil/gas/electricity price hikes like we saw during 2006? So if oil goes up, your electricity bill for your heat pump will rise also.

Wood Pellets Y/N:

Wood pellets are the option I have spent most time investigating, from bulk delivery, individual boiler sizes and dimensions, right down to the building of a bulk store for them. I have a number of concerns though that are preventing me from installing a wood pellet boiler right now. Firstly, this concept that wood pellets are carbon neutral is false. They almost always need to be transported to you, over quite long distances, due to the small number of bulk producers in Ireland. So it is not as eco friendly as more locally sourced wood chips.

Secondly, there are issues with both the quality of the bulk pellets, and the delivery timeliness. The good news is that I can use bagged pellets to get over a temporary wait for bulk delivery, but I am sceptical about the overall quality of pellets being produced here, and about the knowledge that is needed "on the ground" to ensure that the customer gets what he needs. In Austria, they have been using these products for many years; in Ireland we are only about 3 years into the concept of using pellets properly.

A further concern for me is access - I emailed the pellet company to ask them what the maximum lorry size and hose length was but had no reply. Imagine if I built a pellet store only for the truck to turn away as it did not have a long enough hose or could not get close enough to deliver. If you compare this to oil, because we have used it for many years, there are all kinds of truck sizes, hose lengths and so on which can guarantee delivery almost anywhere on the island. The pellet delivery infrastructure needs to ramp up in a similar way, in order to gain mainstream acceptance, in my view. Otherwise it will only be an option for those with ideal sites. 

Finally, I am very suspicious of the cost of these boilers. I touched on this during my original investigation, and feel that the boilers themselves are overpriced for what they do. Either the importers or distributors are taking too much; just having a grant available should not hide the true costs of what basically is just a boiler that heats water using wood! The other bells and whistles (lambda probe, back burn protection etc) should not result in a doubling or tripling of the price.

Wood Chips Y/N:

Wood chips definitely have potential - not only are the carbon neutral but more importantly they are usually available locally, unlike pellets. But like pellets, they suffer the same issues of consistency of supply and consistency of product. Having said that, with wood chips I do have the option of using them in a bespoke boiler or even an open fire. And I could bulk store them to allow them to dry sufficiently before burning. My thinking here is that they could provide a viable backup source of heating. For example, if I were to install a wood chip stove with back boiler in place of my open fire, then while the stove heats the room, any unused heat is fed, via the integrated boiler, into the house heating system. Also, if matched carefully with another heating technology, it may be possible to get a second grant on the wood chip stove!

Solar Panels Y/N:

This is my kind of technology, in that it is free heat from the SUN, with no ongoing 'supply' costs. For starters, the technology has been in use for many years, and because we get the same volume of ambient daylight as Germany, the calculations that they have produced for solar panel efficiency also apply in an Irish context. Also, both flat plate and evacuated tubes are well established technology, so you would be buying a proven product.

The downside is that, domestic hot water (DHW) aside, if I am serious about space heating then the panels themselves will not do the job on their own. Most companies involved in solar space heating quote a maximum of 30% of space heating coming from the solar panels. The reason for this is the trade off between having too much of a surplus in summer and not enough in winter, so they need to size the system to balance the extremes.

So I would be buying a new system but only reducing the existing space heating bill by 20%, right? But, that's not the end of the story. With a solar system you can augment it with any other heating source. So as I mentioned above, I could have woodchips from the wood chip stove adding to the heat, which reduces the oil used even more. And we could even finally replace the oil boiler with a bespoke wood chip/log boiler, so that all the heating is coming from a combination of solar and woodchip products. That's the kind of renewable path I want to take. Once that is done, I can also decide at a later date to change my heat distribution system to under floor and have the solar/wood chip source feed the under floor system instead of radiators. All in all, it would appear that from a truly renewable standpoint, the solar panels prove to be the most 'renewable' of the systems. It is the only option which is free once the capital cost is paid for. And for many people already considering using solar panels to provide the DHW only, it is not that big a step to augmenting the heating system.

Decision made, time to get it installed ......