Calculating the Oil Equivalent of Solar Energy Collected for a Hot Water System

[mgb_phys]

Exactly. Also add: inability to make long distance trips requiring a recharge in route and the recharging stations to go with them.

Plug in hybrids are going to be for around town use. Where the majority of daily trips are less than 10miles and it doesn't take an 8000lb SUV to deliver a 5year old to school.
The first big seller could be electric scooters (ie mopeds) since they are limited to 30mph/50kmh anyway, are used for short journeys and are cheap when a lot of people are going to start wondering if they need to be paying the $30K loan on that 2nd car.

 

[OmCheeto]

I wonder what they'll say next year?

Btw, I just noticed your signature. My company recently did a solar water heater installation and for fun, we calculated how many gallons of oil the collecter saved per square foot per year. Wanna guess what we came up with?

It's going to take 15 years to recoup the cost?

 

[mheslep]

I wonder what they'll say next year?

Btw, I just noticed your signature. My company recently did a solar water heater installation and for fun, we calculated how many gallons of oil the collecter saved per square foot per year. Wanna guess what we came up with?

Spoiler

91 gals/square foot/year in Phoenix, ~half that in Pa.

 

[russ_watters]

I'm going to guess some negative number if you took into account the oil needed to produce and ship the solar water heater.

The oil needed to produce and ship it is built into the price of the water heater, so it factors into a payback calculation...but that isn't what I asked. All I'm asking is the oil equivalent of the sunlight energy collected.

mheslep - you're waaay high. FYi, the array we made doesn't track. You're also not considering the efficiency of the array itself or, more importantly: the hot water demand of the building (the array isn't heating water if it is already hot). It's a school, which doesn't have much demand, but the array is sized appropriately for the limited demand.

 

[mheslep]

The oil needed to produce and ship it is built into the price of the water heater, so it factors into a payback calculation...but that isn't what I asked. All I'm asking is the oil equivalent of the sunlight energy collected.

mheslep - you're waaay high. FYi, the array we made doesn't track. You're also not considering the efficiency of the array itself

I assumed: flat plate tilted at latitude, 7kWh/M^2/day Phoenix. 50% effiency for a solar water heater, and about the same for an oil based water heater (without really checking), i.e. a wash.

or, more importantly: the hot water demand of the building (the array isn't heating water if it is already hot). It's a school, which doesn't have much demand, but the array is sized appropriately for the limited demand.

Yes I didn't consider demand at all.

 

[OmCheeto]

The oil needed to produce and ship it is built into the price of the water heater, so it factors into a payback calculation...but that isn't what I asked. All I'm asking is the oil equivalent of the sunlight energy collected.

mheslep - you're waaay high. FYi, the array we made doesn't track. You're also not considering the efficiency of the array itself or, more importantly: the hot water demand of the building (the array isn't heating water if it is already hot). It's a school, which doesn't have much demand, but the array is sized appropriately for the limited demand.

I only came up with 2.84 gallons per year per square foot.(fixed flat plate at -15 degrees)
I wasn't sure if you were referring to olive, cod liver, or fuel oil, so I used the energy content of kerosene: 134,000 Btu/gal.

But that's pretty cool. I can build one of those collectors for about $3/ft^2.
At $4.00 per gallon of kerosene, my collector should pay for itself in 3 months.

But what on Earth does this all have to do with who killed the electric car?