solar power

This topic hijacked "guns,guns,guns" in politics, so I thought I'd put it up here in case anyone needs to say any more on the topic.
On efficiency, my inverter is a Orion, and I just checked the manual, rated at - over 94%.

Daryl wrote:This topic hijacked "guns,guns,guns" in politics, so I thought I'd put it up here in case anyone needs to say any more on the topic.
On efficiency, my inverter is a Orion, and I just checked the manual, rated at - over 94%.

And another thanks. I was going to ask the brand and stuff but didn't want to put you out too much.

We are generally pretty good at hijacking stuff.

Hey, I got an excuse, I am a scatter brained pedant, well that learned part is lacking.

T2M

We tend to think of solar power as solar electricity. However, solar heat, especially for passive solar houses, pays off better.

You might like to do a search on (Building AND "self heating").

We were able to cut our heat bill by a third of the original amount and also reduce the amount of wood hauled by about half of the original amount when we bought a large batch of used windows. Our south is now a two story solar structure 19 feet tall and 43 feet wide, with enough depth to double as a greenhouse. It still doesn't help much during December and January, especially in cloudy weather.

DDHvi wrote:We tend to think of solar power as solar electricity. However, solar heat, especially for passive solar houses, pays off better.

You might like to do a search on (Building AND "self heating").

We were able to cut our heat bill by a third of the original amount and also reduce the amount of wood hauled by about half of the original amount when we bought a large batch of used windows. Our south is now a two story solar structure 19 feet tall and 43 feet wide, with enough depth to double as a greenhouse. It still doesn't help much during December and January, especially in cloudy weather.

How large a drop in energy capture do you get during the winter months?

Also, what U-rating does your windows have?

We installed triple double-glazed windows (U=0.79) on our house (~3400 sq feet) and added extra insulation and a new exterior 2 years ago, our energy usage is now down to less than 18000 kw/h per year (our heating solution is geothermal) including everything (ie. heating + lights and misc). I think the heating uses about 8500 kw/h a year. Left to do is improving the insulation in the attic since we have some heat loss there.

Currently there is no way to make installing solar heating economically feasible for us since the ROI is many decades away and due to us living so far north the effeciency of solar energy isn't great.

Joat42 wrote:

DDHvi wrote:We tend to think of solar power as solar electricity. However, solar heat, especially for passive solar houses, pays off better.

You might like to do a search on (Building AND "self heating").

We were able to cut our heat bill by a third of the original amount and also reduce the amount of wood hauled by about half of the original amount when we bought a large batch of used windows. Our south is now a two story solar structure 19 feet tall and 43 feet wide, with enough depth to double as a greenhouse. It still doesn't help much during December and January, especially in cloudy weather.

How large a drop in energy capture do you get during the winter months?

Also, what U-rating does your windows have?

We installed triple double-glazed windows (U=0.79) on our house (~3400 sq feet) and added extra insulation and a new exterior 2 years ago, our energy usage is now down to less than 18000 kw/h per year (our heating solution is geothermal) including everything (ie. heating + lights and misc). I think the heating uses about 8500 kw/h a year. Left to do is improving the insulation in the attic since we have some heat loss there.

Currently there is no way to make installing solar heating economically feasible for us since the ROI is many decades away and due to us living so far north the effeciency of solar energy isn't great.

We live in North Dakota. They are just single pane, which is one reason for the high losses. On the other hand, since the contractor rewindowing the school was just going to dispose of the windows, the whole set cost less than $100.00 Almost all our cost was labor - lumber isn't that expensive. My carpentry may not look very good, but it is solid. And the price is right

On a sunny day in December or January, it gets comfortable in the solar, but temperatures aren't high enough to throw heat into the house. We've upgraded about half the attic with a false floor filled with insulation, so far. Also, since the house is a century old, we are putting in some false walls filled with insulation and a wing insulation installation outside. In the summer, we use seasonal heat storage by circulating air through the basement and up into the house - almost eliminating air conditioning. Don't know just how much heat we store this way, but the pipes in the basement are no longer freezing at all.

House square footage is about 5,000 - most of it is only being used for tools, workshop, and storage, especially in the winter. Only five rooms are heated in the winter.

Well as I have egg on my face from my inverter screw up thought I would go and look at stuff more accurately.

Bearing in mind Daryl's comment on manufacture's and marketing I went and looked at a system on the web.

http://www.wholesalesolar.com/1890510/w ... 0-w-panels

It sort of matches the things that spacekiwi posted in a general sense. But it lets me look at individual components.

Then I ran the numbers in the monthly output.

It is a 5.2 kwh system.

Except it only has a 5 kwh inverter (operation at the highest efficiency ("greater than 98%) at all times").

Then I looked at the specs for their monthly output.

707 kwh that is for a 30 day month of 5 peak sun hours times Panel PTC(an cell efficiency rating) * the number of panels.

I am going to simplify a bit also dropping units. Just get the day then divide by 5 to get actual claimed output.

707 divided by 30 equals 23.57
23.57 divided by 5 equals 4.71

So that 5.2 kwh system in the headline is in reality only a 4.71 kwh system by their own specs when new. A loss of ~10%. Which is less than my initial estimate of 15% just for the initial hasty research showed.

As you go through all the fine print other things leap out. That inverter is only guaranteed for 12 years you can get 25 years but that is an added cost didn't look at it.

If you want more fun according to the FPL rate calculator 246 kwh this month is $1.52 less than 10 years ago. It is going to go down another $0.43 on the 1st.

For FPL If you use 1,000 kwh your bill is $99.75. If you go over 1,000 a month it is at a higher rate.

https://www.fpl.com/rates/pdf/residenti ... nation.pdf

https://www.fpl.com/rates/pdf/Jan2016-Residential.pdf

Customer charge will stay the same no matter the energy usage.

So the as of 1 Jan 2016 I am paying 0.08348 per kwh used.

So in 1 year I would will pay(all things remaining constant to past usage) ~3,000 times 0.08348 = $250 dollars.

The system that is advertised closest to match my annual usage (net metering is a very good thing for me house is empty close to half the year.)

http://www.wholesalesolar.com/1890500/w ... 0-w-panels

Which costs $5,532.00. Divide that $250 ~22 year pay back. But I do get based on 4.5 hour days around 1,000 kwh back (if the system actually performs to advertising). Which will probably be something like 40 dollars figuring half back. 25 years $1,000.

As I have said installing stuff here is at least as expensive as the components.

Doesn't include all the other costs associated.

For me I probably wouldn't even take the tax credits other people don't need to support my environmental efforts.

Have fun,
T2M

Just realized that U-ratio in EU is calculated differently (m2 and C) compared to the US, so my guess is that converted to ft2 and F the U-ratio on our windows is about ~0.35...

DDHvi wrote:We live in North Dakota. They are just single pane, which is one reason for the high losses.

Just adding another single pane would almost half your heat loss (if you got panes over). Currently you probably have an U-ratio of >1.0.

DDHvi wrote:In the summer, we use seasonal heat storage by circulating air through the basement and up into the house - almost eliminating air conditioning. Don't know just how much heat we store this way, but the pipes in the basement are no longer freezing at all.

That's a very cheap and functional solution to get a more stable temperature in the house since you are using the basement as a heat sink. You do need to watch out for condensation though.

I've seen solutions where they have poured an extra wide "chimney" full of vents running through it and then they circulate the air through it so it keeps the temperature stable in the house.

Joat42 wrote:Just realized that U-ratio in EU is calculated differently (m2 and C) compared to the US, so my guess is that converted to ft2 and F the U-ratio on our windows is about ~0.35...

DDHvi wrote:We live in North Dakota. They are just single pane, which is one reason for the high losses.

Just adding another single pane would almost half your heat loss (if you got panes over). Currently you probably have an U-ratio of >1.0.

DDHvi wrote:In the summer, we use seasonal heat storage by circulating air through the basement and up into the house - almost eliminating air conditioning. Don't know just how much heat we store this way, but the pipes in the basement are no longer freezing at all.

That's a very cheap and functional solution to get a more stable temperature in the house since you are using the basement as a heat sink. You do need to watch out for condensation though.

I've seen solutions where they have poured an extra wide "chimney" full of vents running through it and then they circulate the air through it so it keeps the temperature stable in the house.

The first year, the air returning from the basement was almost cold until late summer, but with our dirt floor basement, we had to use boots because of a thin layer of mud. Each year since, the condensation element improved. At present, there is only a problem when we get heavy rains in the spring. That problem was there originally in this old house, due to a deeper basement than would be correct for our conditions.

We've since added: a 4 ft x 6 ft radiator in the attic made by soldering used finned tubes from the scrap yard, a 20 inch window fan blowing air through it; PEX tubes from attic to basement, smaller PEX tubes connecting to manifolds, each manifold connecting to half a dozen 1/2 inch PEX tubes buried as deep as we can go in a trench at the end of winter when the water table is lowest. A half barrel and utility pump supplies circulation and a valve in the basement allows drainage in the fall. A thermostat turns on the fan and pump. We can still add one trench the long way, and another across the short way when we have time. In 2015, return water temperature ranged from 45 degF at the beginning of March to 64 degF in October before drainage. The peak was in August at 78 degF return water temperature, with the attic about 90 degF.

In the summer, when it is possible to work outdoors, We are adding "wing" insulation outside to reduce heat loss through the soil. The west side is complete, and we are just starting on the east.

You understand, DIY and minimum capability means affordability (ROI around 20% annual), but increases time to completion. The time is available, since I gave up TV in junior high school. The sun room alone took two years from start until it was functional since only spare time was used.

Have you seen pictures of those giant ant hills in Africa Little by little, you can travel far.

But hey, having a useful hobby is better than being bored, and I can't spend all my spare time reading

BTW, anyone building a new building should search on passive solar designs. The best of them can produce comfort at 5>10% less cost without DIY than a standard building, but it has to be built into the design. Retrofitting is more difficult.

A historical note: The first straw bale house we know about was built in eastern Dickey county, North Dakota, about 20 miles away from us.

Finally found a price online. Waking up in the middle of the night works sometimes.

http://www.collisroofing.com/en-us/resi ... solar.aspx

$11,699 For what I assume is 2.5 kw system covering 200 square feet of roof. That is the system listed on the page. Which more or less matches the panel area on the system I posted earlier.

More or less what I said slightly more than twice as much.

Drops down to $8,189 after credit. Except of course as it is a credit not a rebate and my federal tax liability is only ~$1,500 a year and the credit is only good for 2 years. My cost would be around $8,699 after credit.

To break even if the system lives up to specs and there are no other incidental costs.

From FPL's web site they generate 845 pounds of CO2 per megawatt-hour in 2009(US Average was 1,297). Installed system earlier system was generating 353 kw a month or 4,236 kw a year or 105,900 kw(no it isn't).

IF FPL doesn't get more CO2 efficient I just saved 89.4855
pounds of CO2 with this system. THIS IS GREEN.

For a illustration slowing down 5 MPH on my motorcycle (57 versus 62 on average real world data) saves about 10% of the gasoline. This year on my trip I traveled ~16,000 miles. As a gallon of gas produces ~20 pounds of CO2. So instead of ~50 mpg I get 45.

How many gallons is that 35.5 or about 700 pounds of CO2.

For 5 minutes an hour(while driving) in one year I save ~8 times as much as this entire system.

Food for thought,
T2M

True. I knew someone who made a big deal out of replacing all of their light bulbs with LCDs. Good idea as a 10w LCD does the job of a 60w incandescent, but 10 of them save only 500w an hour.
He drove a petrol V8 Land Cruiser with 220KW, which produced 220,000wh. Not sure of the carbon but would be equivalent to wattage difference.