Maureen:
Since you are building a new house, I would recommend that you work with an architect that is experienced with energy conservation (or willing to work with an expert) to minimize the power needs of the new house, regardless of the source. (wouldn’t it be nice to lower your propane bill, as well?) With good design, you can reduce the total power requirements without going Spartan. Conservation of energy is always cheaper than generation.
Although you wish to avoid them, batteries will be the key to your electric power system. The 400 watts (or whatever comes off the hydro) will not run your hairdryer, which is probably 1200 watts. But hydro runs 24 hours a day, so you store an hours worth as 400 watthours, and that will run your hair dryer for 20 minutes. Looking at it that way, it is 1/24 of your daily energy generation(or 1/48th for 10 minutes). Is the hairdryer something you want/need ? You can run a 23 watt Compact florescent (giving about the same light as a 100 watt incandescent) for 8.7 HOURS, on the same power as 10 minutes of hair dryer.
The question is not about whether or not you have a hair dryer. It is learning about power equivalents and making informed choices. Making the informed decision on each and every light fixture/light bulb and every appliance, large and small. You need to eliminate “size”, and think large or small power consumption. A percolator on the propane stove is a better choice energy wise and price of energy wise than a coffee maker. So, convenience (maybe flavor) versus cost, is your trade off. If you do go for a coffee maker, get one with a vacuum decanter or use a separate decanter or thermos. The warming plate used with the glass pot coffee maker is a non-essential power draw.
Just by adding batteries (and an inverter) to your generator system would cut down on your fuel bill. Gensets are most efficient when loaded above 50 percent. There is a portion of the 10 hours a day, where your generator is running to supply small amounts of power. By charging batteries while the generator is already running, you could then run small loads for a number of hours, saving that number of hours of fuel burn. I would consider them, even if for some unknown reason, you decide not to do the hydro.
Moderately priced batteries (well cared for) should last 5 years or so. Top of the line batteries often go 10-15 years, and I know of some pushing 20.
The cost of the batteries will depend on quality and sizing. A bank is typically sized at about 5 times your daily electric use. So the smaller that daily use number is, the smaller the bank and the less it will cost.
I would guess-timate that you are using 15-20kWh a day in your current setup and it is costing something near $30-35 a day. So, you are currently paying somewhere between $1.50 and 2.33 per kWh. Regardless of the unit price, $30 a day 365, is about 11,000 a year. So even if the hydro only provided half of your energy needs, that’s about $5,500 a year in savings. You will have a fairly short payback period.
I would recommend that you work towards a hydro system and diesel genset combination with batteries and an inverter. I am not sure that eliminating “diesel” is a good idea. Minimizing it to as low as reasonably achievable, yes. There are propane gensets available, but propane is generally 2.5 times more expensive than diesel, on a per kWh basis. (By the way, diesels run great on #2 stove oil.)
I am fairly certain that the electric loads can be easily dropped down below 9.6 kWh a day. If you achieve that, you could avoid gathering the additional flow. During the 20gpm or greater flows, you could get all of your electric power off of hydro. The genset could make up the difference during low flow periods, as well as providing all of your power in an emergency. Even a cheap part that fails in the hydro system or the inverter might cause you to be without power for a number of days or possibly months. Being able to bypass them and run directly from a genset, would make a world of difference.
Here is a energy cost chart that was done by a Juneau firm. It is out of date (98), but it could be easily updated to current prices. And you might want to add a line for #2 diesel, at 140,000 BTU/gallon. And possibly Gasoline at 115,000 BTUs/gallon. (That BTU difference is major reason diesels are more efficient than gasoline generators.)
http://www.plumbandheat.com/costcomp.htmlEven as is, it raises of the question of why are you heating water with propane instead of fuel oil or diesel. (There are 4.24 lbs of propane per gallon, if you are getting price per lb.) Based on the 98 prices, one would be getting 2.63 times the BTU’s per dollar with fuel oil, as compared to propane. It may not make a big difference for 4 weeks a year, but over 52 weeks, it really does. Propane would make sense for tankless on demand heating, but for tank type heating, no.
The statement “I really want to get away from gas and diesel, but I can manage propane shipments once a year.” does not make any sense (to me anyway). Unless you have a propane tank of gigantic proportions, you will need more than one delivery a year. Remember you will need 13 times (52/4) the quantity that you have been using. More than that if you shift more demand onto it. So with more than one delivery, does it make any difference whether it’s a “propane boat” or a “fuel oil boat” ? .
You need 1.53 gallons of propane storage for every gallon of diesel/stove oil storage to break even on BTU’s, and you are/were paying 2.63 times the price per BTU. You may still want propane (I don’t like fuel oil flavored eggs), but I would look at having an oil system. You might also look into bulk delivery of fuel oil as compared to drums.
By re-assessing all of your energy needs, minimizing where possible, and selecting the right source for the task at hand, you have a wonderful chance to lower all of your energy costs.
A question, if your water tank is about 300 feet and it’s the same water source, why are you talking 200 for the hydro. Are you pumping up to the tank, extra length of new piping to gain the last 100 feet, or just being conservative ?
Ken
