Cost of hot water

[Kenpobldr]

I recently installed a pellet stove to heat my home. We still currenty have to heat our domestic hot water thru the tankless coil on our oil boiler. I am looking to see is anyone knows of a cost to energy calculator to heat water for oil/electic/gas/solar. Oil is currently $5.00 per gallon in our area while electric currently costs .12 cents per KWH and unfortunatly we dont have the option on natural gas. I have looked into solar a litte bit but it seems that we would have to spend at least 4k to have that done and the pay back seems very long term.

 

[steam man]

We just did a thread here: https://www.hearth.com/talk/threads/19035/. I did the numbers but don't guarantee anything. You can plan on one thing-electrical rates are going up so a payback on solar over decades would be a plus. There are also tax credits to help out.

 

[SteveT]

Here's a calculator:

https://www.hearth.com/econtent/index.php/articles/fuel_cost_comparison_calculator/

Take another look at your electric charge. Are you considering only the "Generation Charge"?

I am also in eastern Mass and pay $0.19/KWH ($0.118 for generation charge plus $0.072 for delivery charge). I think that is fairly typical around here.

From what I've observed, solar can save a lot under the right circumstances (mostly rebates) but it probably won't work as the only energy for heating water year-round. It does a great job of reducing energy needs by adding energy to the water source, but for cloudy/winter days it won't work as the sole HWH.

 

[lecomte38]

I am very interested in this also. I shut down my Budarus boiler with seperate a Super Store hot water tank in favor of running the electric hot water tank. Oil at $4.99 or electric at 16.5 cents /kwh My electric tank is right under the kitchen/laundry - instant hot water vs 1 minute to pump hot water from the boiler system, bathrooms are equal time. Wood pellets for heat this winter and looking at water generation off the pond in the back yard - 3.5' head on a small brook.

 

[Highbeam]

It seems quite silly to run an oil boiler just to indirectly heat your domestic hot water. It makes sense if you have a hot boiler for heating but since you've switched to pellet, I would seriously consider moving to an electric tank heater. They are cheap to buy, only need a 30 amp circuit, and "bolt in" in place of, or beside the indirect heater.

The cost of energy calculators are going to be misleading in this case. The efficiency of your boiler to heat its fluid is not the same as the efficiency that it heats your domestic hot water indirectly. Your situation is similar to idling a truck's engine to run the headlights to light the driveway.

 

[cbrodsky]

For many people, it will make sense to go to electric if you have a tankless coil. There is tremendous standby loss in an oil boiler as compared to a well-insulated storage tank system.

One of the most significant factors in high ROI for our solar HW system was finally being able to shut off our boiler much of the year. With our woodstove, we only need to have the boiler on 3-4 months a year for supplemental heat - the shoulder periods it stays off and we use electric to make up any gaps that the solar can't meet.

Funny to think that I came up with 15% ROI based on $2.25/gallon oil - now that's more like 35% annual tax-free ROI. If only my 401(k) was doing that well

-Colin

 

[galindog]

I have a furnace for my baseboard heat and domestic hot water and have cut off my oil usage from 1200-600 gallons since getting a wood stove.During the summer, the furnace runs to heat our water which seems like a waste. Various forums here have suggested getting an electric water heater ($1000 installed) and a solar hot water system which I surveryed to be around $12,000. In spite of the tax credits, would'nt the solar have a breakeven of 5-10 years down the around inspite of oil at $5 and elec at 20 cents/kwh?
Does solar lend itself to DIY installs? in order to save the labor component of this $12000? Thanks

 

[cbrodsky]

I have a furnace for my baseboard heat and domestic hot water and have cut off my oil usage from 1200-600 gallons since getting a wood stove.During the summer, the furnace runs to heat our water which seems like a waste. Various forums here have suggested getting an electric water heater ($1000 installed) and a solar hot water system which I surveryed to be around $12,000. In spite of the tax credits, would'nt the solar have a breakeven of 5-10 years down the around inspite of oil at $5 and elec at 20 cents/kwh?
Does solar lend itself to DIY installs? in order to save the labor component of this $12000? Thanks

$12K would be a much tough case to make for solar. In my case, we spent $4,000 after getting about $4,000 in tax rebates from the original $8,000 cost.

At $5/gallon, my long-term ROI works out to 27% annually over the life of the system. If I had paid $12K, it would only be 12% - and I wouldn't assume oil will stay at $5/gallon. If I drop oil price back to $2.50, the ROI with a $12K install in my situation would have been only 5%.

The tank install and plumbing connections are definitely in the realm of a DIYer who has basic soldering experience, but I would leave the roof install to professionals. The panels are large and heavy.

A friend is putting in a $2000 heat pump water heater - I will be curious to see how that works out.

-Colin

 

[mayhem]

I have looked into solar a litte bit but it seems that we would have to spend at least 4k to have that done and the pay back seems very long term.

Do some math based on your summertime hot water usage and extrapolate out the remainder of the year to figure a ballpark oil consumption for your hot water needs. I burn about 300 gallons of oil annually just for hot water...at $5 a gallon thats $1500 a year. A $4k solar installation would pay for itself within 5 years (assuming that the solar would not address 100% or your needs and that some of your DHW heating would come from either an electric coil, propane or oil).

 

[cbrodsky]

I have looked into solar a litte bit but it seems that we would have to spend at least 4k to have that done and the pay back seems very long term.

Do some math based on your summertime hot water usage and extrapolate out the remainder of the year to figure a ballpark oil consumption for your hot water needs. I burn about 300 gallons of oil annually just for hot water...at $5 a gallon thats $1500 a year. A $4k solar installation would pay for itself within 5 years (assuming that the solar would not address 100% or your needs and that some of your DHW heating would come from either an electric coil, propane or oil).

I also think it's valuable to look at return on investment, as payback often discourages people if it's more than 1-2 years.

In the simplest form, imagine if you put $4,000 in the bank. Today, you'd be doing well to get 4% in a CD, which you'd pay tax on, so maybe you take home 3% of that $4,000.

Now imagine if you put that $4,000 in the example above. You'd save $1,500 of take-home pay that would have gone to oil, which is equivalent to 37.5% return. I wish I could find more investments like that! And with the high reliability of a modern solar HW system, you can bank that return for a good 30 years.

-Colin