Solar Panel or Wood pellet boiler for water heating

flocker

Just asking the question.
If you used a heating system that has independant hot water ( you can heat the domestic cylinder separately) and used a wood pellet/chip boiler. How viable would a solar system be? Yes it would pay for itself at sometime but all the payback times l have seen are based on oil being the fuel.

Evergreen

Hi Flocker,

That's a good question. I think that if you are looking at it only in relation to financial payback then it probably will be a very long time.

Let's do a comparison based on 2kW 2 hours per day 365 days per year (for ease of calculations I have ignored the electricity used to power the solar panels pump and the boilers fan system.

Fuel Type Electricity
Cent/kW 12.54
EUR Day 0.501
EUR Year 183

Fuel Type Oil
Cent/kW 7.25
EUR Day 0.29
EUR Year 106

Fuel Type Pellets
Cent/kW 3.40
EUR Day 0.136
EUR Year 50

Cost of 6.1m Solar System EUR 4,295
SEI Grant EUR 1,800
Total Cost EUR 2,495

Payback period

Comparing to electricity 13.6 years
Comparing to oil 23.5 years
Comparing to wood pellets 49.9

I see your point

Highway

Does this mean that in a new build, it's better to just install a wood pellet boiler for both hot water and heating, instead of adding a solar panel to boost the hot water?

I am trying to decide on a heating system for my new house, and the more i research, the more confusing it becomes!

Is there any situation where geothermal is better than wood pellet boiler. A supplier has told me that a bore hole heat pump would cost about €1200 p/a in electricity to run my underfloor heating and hot water. House is approx 2500sq ft. Two storey.

The initial outlay is very expensive, and I'm looking at other options. Currently i thought that a wood pellet boiler and solar combination was looking good, but this post appears to blow that theory! (at least adding the solar part)

I believe that 2000lts of oil would be required annually for a house of my spec, and apparently this equates to approx 4 tonne of pellets, which is half the cost annually.

So, is pellet better than geothermal, and is solar worth adding to pellet systems.
Thanks,
Highway.

Evergreen

Hello Highway,

My cousin installed a geothermal system in his house last year, and as is becoming common the sales guys under estimated the size of the system he needed in an effort to compete on price. As a result when the weather got cold the system wasn't able to keep up with demand and it had to turn to the back up system to make up the shortfall - namely electricity. His ESB bill for Jan-Feb was almost EUR 600 which is a heck of an amount considering the house is empty from 7:30am to 5:00pm every day. My point here is do your sums before committing to such a system.

If you are going to install a pellet system then you should consider installing it in such a way that it is forward compatible to adding a solar system further down the line. I don't mean a solar system that heats hot water but rather one that can be used to contribute to heating your house. A good boiler can take control of the Solar collector in such away that if there is enough heat coming from the panels the boiler will not switch itself on.

Send me your email address vis PM and I can email you a circuit diagram to show you how such a system is setup.

Regards,
Ned

flocker

the more i research, the more confusing it becomes

I have to agree Highway, there are a lot of options out there and it's hard to know which is going to be best long term. That is why l asked the question.

For what it's worth, I'm not convinced geothermal is the way to go long term, it's very dependant on electric (to run the heat pumps and top up the hot water cylinder) and the ESB, and their generators are tied to the price of oil.

It maybe worth still looking at the solar panels in conjunction with a thermal store/heat bank and wood burning boiler. Some info at www.heatweb.com

So, is pellet better than geothermal, and is solar worth adding to pellet systems.

Well, that is the question to which l have my opinion and 100 may have a different view. It looks like we are both going to have to do more research. Good luck whatever way you decide.

Highway

Great to get replies so quickly!
Does anyone know of a place to get expert independent advice on such a topic. I would consider paying someone who can provide totally unbiased comparison advice of all systems specifically for my property. Does such a service exist.

Wood pellets seem to be winning the argument, if I invest enough up front, which i have no issue with, on a top class system.
I can make provisions for adding solar later fairly easily i believe. Basically a storage tank with an extra coil or something.
I'm a bit concerned now about the comment regarding the potential for pellet prices to wildly fluctuate, this would completely alter the equation, but of course, noone can see into the future, so who knows.

Flocker, would appreciate if you could keep this thread updated with your research, and I'll do the same.

Evergreen, I'll PM you my email address, and you can send the diagram. Thanks.

Highway.

flocker

Highway,

you could keep this thread updated with your research

Bar searching the web the next research opportunity is the Energy show at the RDS, which l will be attending. It maybe worth your while too.

Highway

Yes, I was intending to, but work is getting in the way of a lot of things at the moment.
Thanks for the link. The info is very clearly written, straightforward explanations.

Dj

rooferPete

Hi flocker,

The less regulation by that I mean testing the quality of each product and assigning it an energy efficiency label the more confusing the present grant scheme will become.

Evergreen has provided a nice table that is easy to read and understand, then the geothermal post which is really a good example of what can go wrong when "Sale Closers" are relied on.

There are good geothermal systems working properly but we walked away because of the differences in the numbers provided by different manufacturers.

The day may come when a generator be it wind, photovoltaic or old time water will be efficient enough to run a geothermal system, the question I ask people who are considering ground loop systems was was a proper site survey carried out ?

To date I have not had one answer yes, the nearest was a rep said he would call back when the foundations for the garage were dug out, the best geothermal system will have extreme difficulty working in shale or gravel type ground conditions.

I recently saw a two metre solar panel (tube) that was sealed at the bottom using neoprene rubber which I know is is proven to break down under UV light , the system was cheap at a little over €600.00, the grant would cover the cost of the panel.

Regardless of the grant that is an expensive system because it will have a life expectancy of about ten years, I believe that product should not qualify for the grant because the average consumer may take SEI approval as meaning the system is a good one.

As to installing a reserve coil in the cylinder I agree with that because it leaves the option open for solar at a later time, however the supplier should be told to clearly mark the coil for solar and the one for the primary heating system whichever one you choose.

There are a few consultants who will advise on your system, however I am not sure if totally unbiased is really possible, some consultants can have their own agenda, others will learn just enough about each technology to appear knowledgable but don't keep up to date about changes in each technology.

I have noticed different customers reffering to heat stores and buffer tanks as if they are same product, another I have noticed is people not asking if the heat store (cylinder) is glass lined for hard water areas (lime).

There are a lot of questions that remain unanswered and will remain that way until the consumers stop looking for the cheapest Euro cost of a system and not only ask the questions but wait until they are answered.

.

andmurray

Hi All,
Am delighted to have stumbled across this forum and to find such good advice here. I am literally at the 'Make your mind up time' stage re woodpellet and solar panel system. I have done some research into it but find it difficult to get really cast iron independent advice. Here are a couple of questions some of you may have answers to. I will be passing on my experiences to this forum as I proceed.
A. I am definitely going with woodpellet as primary heating source. I have heard of 'Opop' boilers which are competitive price wise but does anyone know about quality, efficiency ect?
B. Aquatech, somewhere in Cork, do a complete solar panel system, including dual coil tank for what again appears to be a competitive price. Does anyone know anything about their system?
C. Is it ' Overkill' to have solar as well as woodpellet? I am thinking that in summer, the solar will do for my hot water and a solid fuel stove/roomheater will give sufficient heat much of the time. Am I right in thinking thus or am I totally off the mark? I'd appreciate ANY advice as I am getting very close to decision time. Thanks.

yop

Personally I do think that the pellet stove on it's own would/should be sufficent enough for heating and DHW. Solar panels seem to have too long a payback to be worthwhile.

On the geo, we have ours in and the only worry I would have with it is the electrical hikes in the future. As Pete said until a genie or wind turbine comes out to power these we are at the mercy of the price of oil and electric.

On the pellet stove, my only concern would be that there will be so many people buying them that the price of the pellets will rise due to shortages and of course the greed that is rife in Ireland to "grab it all"!!

On a recommendation note and we are not mates or work partners or anything but I queried RooferPete on the boilers and stove etc and must say all the info I received was top notch. Personally on choosing an alternative heat source, dealing with someone who knows their products and stuff is worth the extra expense

towbar

andymurray,

In exactly the same position as yourself and have quotes for pellet boilers from 4500 to 16k +vat. Initially I was sceptical but there is a genuine difference in functionality between the boilers on the market. I dont want to in any way knock the lower cost models and may still go with one of them as they will do the job too but having reviewed the features of some of the more expensive models and I am hoping that they can deliver greater fuel efficiencys and longer life operation.

I have loosely been working off the following list - maybe others could add to it as a means to compare and contrast

1) Ok so I admit I tend to start by asking the price but its important to know what price includes
Instalation - this can be done by an experienced plumber but the supplier or registered installer muyst commission the system.
Also most prices for instalation will exclude the chimney flue.
2) Bulk store and feed system - most prices wont include this but the 16k one above did - the supply and installation of a bulk store is probably 2.5-3k but as these threads point out you can DIY.

Feed system - Some of the sytems have vacuum feed systems that suck pellets form the bulk to the local store. The vacuum attachments can cost up to 2k and may or may not be included. Can the boiler be filled manually?

3) warranty - seems 3 and up to 5 year parts and labour is possible with some

4) modulation. This one is tricky as most say the boiler modulates. Essentially it means that the boiler doesnt have to run at 100% all the time so as temperature of water reaches set point boiler slows off rather than cycling. Essentially you need some way to slow down the feed of pellets into the burner. The range of inputs here from simple room thermostats to mixer valve sensors even to weather sensors.

5) Burn back protection - ensure that in the event of a problem there is no way the boiler can burn back into the feed store. Some drop pellets into burner, some use meter wheels and some

6) Buffer or not!!! Major debate - some say must use buffer some say not. I havent a clue but again it is an item to consider on pricing as the cost of the buffer tank is not insignficant and in an ideal world it seems that a buffer is best although personally I still think it seems like a bit of waste when we are hoping we have insulated and zoned to only require minimal heat input - why heat up 1000l of water even if it does retain its heat.

7) References. Yes there are not many installed yet but some companies can supply reference customers.

8) Multi-fuel - Found one boiler than burns pellets, grain and maize - tempting but worried what has been sacrificed to achieve this.

9) Lead time - varies from 2-12 weeks.



Sorry if I have confused you even further!!

On solar I reckon savings are about 100-150 per annum as against 900-1000 for pellet so my view this minute (could change in next minute) is to put the extra money towards a good pellet solution however I will install a 300l dual coil hot water tank to facilitate solar in the future.

SachaJ

Sorry, coming very late into this topic....

With all the discussions on solar heating above etc, has anyone seriously considered wind turbines? See link:

http://www.navitron.org.uk/wind_turbine.htm

I'm a bit of a novice, but I'm starting a bit of research into a possible new build.

MysterFixIt

For some interesting information have a look at EcoLogics Quintin Gargans site on wind and solar power. He is a very interesting guy and he is highly principled in business. If you are considering any of these alternatives it would be worth your while talking to this guy.

Especially read the sections on his site on grants and the rip-offs that are going on both in Ireland and the UK. Where you can end up paying more by going for the grant - and being landed with the price gougers, than by going it independent.

http://www.ecologics.ie/?page_id=5

http://wood-pellet-ireland.blogspot.com/

bushy...

SachaJ wrote:

Sorry, coming very late into this topic....

With all the discussions on solar heating above etc, has anyone seriously considered wind turbines? See link:

http://www.navitron.org.uk/wind_turbine.htm

I'm a bit of a novice, but I'm starting a bit of research into a possible new build.

Hi, i've seen a few of the above gennies, they are well priced,spares are very cheap, guy is sound to deal with but they are a little bit noisy / vibe prone though , would be grand if not too near your house

Do-more

Just to confuse the debate further:D I have come across this company in Sweden that does a combination of geothermal and solar www.eviheat.se no english on the website but click on "sol + värmepump" on the left hand side and you will get diagrams of how the system works.

It uses solar when available to heat water + house, geothermal kicks in when not enough solar energy is available. When no heating is required excess solar energy is dumped into the ground via the ground loop to be recovered later. They advertise a COP of upto 7. Don't know if anybody can supply such a system locally.

Gambler

MysterFixIt wrote:

For some interesting information have a look at EcoLogics Quintin Gargans site on wind and solar power. He is a very interesting guy and he is highly principled in business. If you are considering any of these alternatives it would be worth your while talking to this guy.

Especially read the sections on his site on grants and the rip-offs that are going on both in Ireland and the UK. Where you can end up paying more by going for the grant - and being landed with the price gougers, than by going it independent.

http://www.ecologics.ie/?page_id=5

http://wood-pellet-ireland.blogspot.com/

Hehe That's my old man yer talking about Strange seeing your dads name on boards.ie from someone else I must say.. (Oh and it's Quentin )