# Energy options for the old island homestead



## Cynnergy (Feb 25, 2015)

So, hubby and I _might_ have the opportunity to reno my great-grandparents house on the island (off-grid) and do it up for a vacation rental.  It was built in 1937 but no one has lived in it since 1981.  The family has kept up the essentials - part of the roof and siding was redone a few years ago.  Minimal to no insulation - about 2000 sq ft over two floors, plus a damp basement.  It would likely only be open during the summer, although I would like to put a wood insert in the fireplace so it could be opened up for winter use by the family - I have my eye on the Enviro Boston 1700.

However, there is currently no heat or hot water system in the house.  It originally had a wood furnace, presumably with ducts sized for convection (no electricity for a blower).  

Usual hot water for off-grid is propane (either tank or on-demand).  We will have to have propane for cooking and likely a dryer (for bedding).  However, getting propane to the island is a hassle and I can't woman-handle 100 lb propane tanks by myself.  I would like to minimize that if possible.  We do have some electricity (currently from a generator but we are looking into renewables).

Alternate heat would definitely be nice.  The house is right on the water and it can get chilly at night, even in the summer.  I am wary of lighting woodstoves in the summer - cedar shake roofs and dry weather and no fire department just seem like a really bad idea.  By the end of September (prime fishing season), heat would probably really be needed.  

I have no idea what it would cost, but would a combo pellet boiler/solar hot water (with water-to-air heat exchange in the furnace plenum) give some shoulder-season heat and DHW?  

Any other ideas?

Here are our usual forms of transport:


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## Where2 (Feb 25, 2015)

I love the "usual forms" of transport. (of course, I would, I live on the water...) I think you can haul plenty of insulation out to the island on that landing craft. Follow the common air sealing techniques to help keep the heat you generate inside.

If you were just using it for cooking and on-demand hot water, how long do you think two 20lb propane cylinder would run? They are at least somewhat portable without needing a hand truck.

P.s. Looks like a splendid place to spend the summer, based on the photos of the harbor.


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## Cynnergy (Feb 26, 2015)

Hmm guess this is a better question for the pellet pigs .  I will try there too.

For cooking, I think propane would run a pretty long time.  Heavily used BBQs get several weeks out of a 20lb tank, right?  My parents get about 4 months out from 2 100-lb tanks for cooking and the dryer.  But most of the time it's only two of them and they have an oil hot water heater.  I really don't want to go with oil, but it's a possibility I guess. 

We once ran a propane hot water tank (regular one) off of a 20 lb tank and we got 4 showers/day for 4 days (plus some dishwashing) out of it.  For a house that will sleep up to 12, that's not a lot, even if you save 50% on fuel with an on-demand system vs. an ancient tank system.  Maybe there was something wrong with the system though - *does anyone have real-world experience with how much fuel an on-demand system uses? *


Re: insulation.  I really don't know how to insulate it, short of ripping off all of the new siding and roofing and wrapping it in foam board.  I can insulate the floor joists between the basement and the 1st floor easily so I will probably do that - I don't really want to insulate the basement because a) it will be an awesome root cellar and b) I don't know if we'll ever solve the moisture issues entirely (it has an open sump and a spring just uphill), although I'm sure we can make it better and we will be working on that.  

Re: roof and walls - the interior walls are lathe and plaster and there is only a tiny amount of attic space in the very middle of the house because of several dormers - much of the 2nd floor is in the roof space.  I have no idea how to insulate that properly while still maintaining the proper vapour retarders, etc.  I don't think you can dense pack cellulose in a hot roof?

http://www.greenbuildingadvisor.com/blogs/dept/qa-spotlight/can-cellulose-be-used-unvented-roof

Is there any other way to retrofit insulation inside lathe and plaster walls/ceilings other than cellulose?

It's a little hidden here by the overgrown vegetation, but you get the idea.  Sort of a primitive Cape Cod design.  It is lovely here in the summer!  A bit windy, but absolutely beautiful.  I am incredibly lucky to have grown up here and possibly have this opportunity.


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## begreen (Feb 26, 2015)

Cool, which island? I want to visit you in the summer.


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## Cynnergy (Feb 26, 2015)

Hardwicke Island - near Sayward, BC.  Watch out for the westerlies - if it's blowing over 25 knots in Johnstone Strait I am very picky about only going out on a flood tide.  You are more than welcome BG but I may rope you into some reno's (or PV consulting)!  

If we take on the Big House project, we will aim to have it completed by 2018 - 100th anniversary of the family being on the island.  My great-grandfather is 2nd from the right - just a kid in this one.  This pic is on Broughton Island, a bit further north of here.  And that's a giant red cedar, for anyone not familiar with the PNW species.  You could make a lot of super-cedars out of that one, although truth be told I wish there were a few more that size left around here.


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## woodgeek (Feb 27, 2015)

On the propane issue....the important bit might be a low-flow showerhead....they have improved a lot.

If 2 gallons per minute for 10 minutes, heating +50°F, that works out to about 8000 BTUs per shower, call it 10 kBTU with burner efficiency.  1 pound of propane is 21 kBTUs. So figure 0.5 lbs of propane per 'low-flow' shower in a 80% efficient heater. 

A 20 lb tank should be 40 showers on paper, versus the 16 you cite.


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## EatenByLimestone (Feb 27, 2015)

You can also buy 40 lb cylinders too.


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## Cynnergy (Feb 27, 2015)

Thanks for running the numbers woodgeek!  Maybe we could do a solar pre-heat tank for the on-demand and make that stretch out even longer.  Plus a solar shower outside.  

The transport problem really comes when having to get the propane tanks in the truck bed.  Maybe we can rig up a mini-crane of some sort? 

I don't think I can even lift a 40lb tank to get it in the small boat when full.  A 20 lb-er is about my max.


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## valuman (Feb 27, 2015)

You could institute a two person per shower minimum and cut the fuel for shower water in half, just like that!


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## EatenByLimestone (Feb 27, 2015)

Cynnergy said:


> Thanks for running the numbers woodgeek!  Maybe we could do a solar pre-heat tank for the on-demand and make that stretch out even longer.  Plus a solar shower outside.
> 
> The transport problem really comes when having to get the propane tanks in the truck bed.  Maybe we can rig up a mini-crane of some sort?
> 
> I don't think I can even lift a 40lb tank to get it in the small boat when full.  A 20 lb-er is about my max.




How do you do with 5lb fuel cans.  Those are 40lbs too.


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## DBoon (Feb 27, 2015)

Nice setup - I'm envious.  

From the photo and the shadows, it looks as if you have pretty good sun exposure.  For a summer only house, your solar potential might be pretty good.  I would consider setting up a couple of 4 x 8 foot collectors on the roof and building a 250 gallon storage tank to pre-heat (or maybe completely heat) a lot of water, and then rely minimally on propane for the additional HW heating - a small on-demand HW heater may work well for you in that case, with the low-flow showerheads as described earlier. If the tank was big enough (250 gallons), it wouldn't overheat in winter and/or you could attach it to a radiator and a control to pull heat out of the tank and heat the house when you are not there. the build it solar website has a bunch of resources to describe how to do this, at minimal cost if you are handy.  An even larger tank (400 gallons) with more panels gives more ability to store extra heat for when you need it, and mitigates the overload conditions (you would have to do some calculations to size this correctly...)

Regarding insulation, a good installer should be able to pump insulation into wall cavities from the outside with minimal damage to the shakes.  They would take a shake or two off at a top and bottom location in one vertical cavity, pump it in, replace the shakes, then move on to the next cavity.   You might have some re-finishing to do to the shakes when they are done.  Some people use cellulose for the insulation, and others fiberglass.  I had fiberglass put in my wall cavities (didn't want the dust from cellulose as I have allergies to dust).  At the end of the day, both materials will work well, but there are those who will debate the merits of each. 

An out-there idea would be to use an on-site bio-digester for on-site methane production from toilets and food scraps.  You would have to be willing to manage it, but it is possible and there are internet resources for this type of thing.  It does involve some lifestyle and management changes.  But, you could mitigate the need for propane, perhaps completely, depending on demand.  It's not as crazy as it sounds for this type of remote location, and sounds a lot better to me than hauling cylinders of propane back and forth on a boat...

You didn't mention electricity, but a 1kW off-grid system might not be too costly, and give you a lot of capability.  I think good, reliable, long-lived batteries might be about $1000/kWh, and if you had a 1kW solar PV system, then you could get 4kWh of battery storage (perhaps almost 2 days of storage, if you are frugal) for a reasonable price. Then (you mentioned a damp basement), I might invest in a Geyser heat pump water heater (HPWH) that would only run when the sun is shining and I had power production. These use about 550 watts/hour (not too much).  It could heat up the 250 gallon tank mentioned previously, and use solar PV power at the time of production (i.e. no extra cost to size batteries for it) to heat hot water and dehumidify the basement at the same time during the season when humidity might be highest, solar PV potential is best, and occupancy may require more hot water. 

Looking forward to hearing your updates a couple of years down the road...


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## STIHLY DAN (Feb 28, 2015)

Solar hot water with storage and radiator sounds like a great idea.


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## begreen (Feb 28, 2015)

Given our generally dry summer weather that sounds like the best option. Let the sun do the fueling for you.


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## Highbeam (Mar 7, 2015)

If you can't lift the typical 30# (7.5gallon) rv size propane tanks then you won't be able to lift a 40# sack of pellets. I would stick with propane and make a simple hoist or crane setup to help you pick the 100# tank (weighs 180# full) from the pickup. A hand truck makes them easy to move around once they are on the ground.

Think cherry picker engine hoist for cheap premade hoists.


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## velvetfoot (Mar 7, 2015)

Would something like this work?  Of course it'd be a drag if something broke and it fell to the ground.  
http://www.harborfreight.com/12-ton-capacity-pickup-truck-crane-with-cable-winch-60731-10018.html


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## stoveguy2esw (Mar 20, 2015)

the "off grid" lifestyle is not really up my alley so to speak as i dont know a huge amount about it  BUT i noticed mention of wood heat. now, ive been researching Peltier generators (TEG's) for a while now looking at applications that might be useful in my line of work and thought i'd drop a website here for you to look at for potential power generation using the wood stove for a generator. its pretty neat technology.

anyway , here's a website to take a look at    http://tecteg.com/


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## Lake Girl (Apr 11, 2015)

Cynnergy - beautiful place.  Wonderful that you have the history of the house and family all in one



velvetfoot said:


> Would something like this work?  Of course it'd be a drag if something broke and it fell to the ground.
> http://www.harborfreight.com/12-ton-capacity-pickup-truck-crane-with-cable-winch-60731-10018.html



We had one of those - just have to be careful of the brake mechanism.


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## Cynnergy (Apr 17, 2015)

Wow thanks everyone for the replies!  Things got a bit crazy at work so I was off the forums for a while.  

Some excellent food for thought here - thank you!  I LOVE the pickup crane.  I can move 2x 5gal jerry cans at a time (slowly) - I'm reasonably fit, just female .  Propane tanks are just really awkward though - I couldn't carry 2x 20lb propane tanks at a time.  I've never tried a 40 lb'er, might be worth a try.  I saw a local propane delivery truck the other day that looked like a flatbed pickup with a big tank on the back (500 lb maybe?).  If we could get that on the Sealander, it might work too.

The storage idea is intriguing too - I would need pressurized storage, right?  I'm not very familiar with storage systems, but I'll go to build it solar, thanks @DBoon


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## DBoon (Apr 17, 2015)

Cynnergy said:


> I would need pressurized storage, right?


Nope, just a simple unpressurized tank and heat exchanger you could build yourself for a few hundred dollars.


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