House electricity bills sky high

[ken0042]

Simple math. 3000 watt solar system; assume only 6 hours per day of useful solar activity means you are putting 18 kw/h of power into the grid per day. That's 540 kw/h per month.

By comparison, my bar fridge uses 60 watts at peak. So assuming it runs 50% of the time (which it runs far less), that is .72 kw/h per day or 22 kw/h per month. So it would only use 4% of my solar output.

[DoubleK]

It may use 60 watts at peak, but that doesn't help you when your solar panel doesn't supply enough current to turn the motor.

The 'simple math' you quote is undone by physics.

[bizaro86]

Originally Posted by ken0042

Simple math. 3000 watt solar system; assume only 6 hours per day of useful solar activity means you are putting 18 kw/h of power into the grid per day. That's 540 kw/h per month.

By comparison, my bar fridge uses 60 watts at peak. So assuming it runs 50% of the time (which it runs far less), that is .72 kw/h per day or 22 kw/h per month. So it would only use 4% of my solar output.

A better way to do that calculation is with PV potential based on solar insolation data. Your tax dollars happen to provide that service here: http://pv.nrcan.gc.ca/index.php?m=r

In Calgary, NRCAN estimates 1292 kWh/kW per year. So your 3000 watt system would generate 3876 kWh per year, or an average of 323 kWh per month. The average is misleading, it'll be much more in the summer and less in the winter. That also assumes you have the panels south facing and tilted at an angle equal to the latitude. Any other single orientation will produce less.

[ken0042]

Are you saying that the thousands of people who are currently running on a solar setup like I mentioned are not getting the power from their panels? I've given the math and know of thousands of people doing this. I have even seen a few setups like this running in person. If you wish to disprove me, please do so. Just saying you think I am wrong does not make it so.

[accord1999]

Originally Posted by ken0042

Are you saying that the thousands of people who are currently running on a solar setup like I mentioned are not getting the power from their panels? I've given the math and know of thousands of people doing this. I have even seen a few setups like this running in person. If you wish to disprove me, please do so. Just saying you think I am wrong does not make it so.

You're getting power; it's just that the winter months are going to be much less than in the summer because days are shorter, the light is weaker and there will be more cloudy periods blocking the light.

Using Germany as an example (which covers a similar latitude range as Southern Alberta), the amount of electricity generated by solar in the Dec/Jan months is about 1/5 of what it is in June/July (page 11):

http://www.ise.fraunhofer.de/en/down...rmany-2014.pdf

[GGG]

Originally Posted by DoubleK

The electricity delivery charges aren't consumption based.

If you believe solar has the ability to satisfy your household's electricity demand and provide surplus power back to the grid, I'd like to see what you are reading. In reality, it won't even keep your beer fridge running.

I think the point here is they should be. If everyone used half the electricity the delivery costs would be less. It wouldn't be linear with consumption but some portion of the delivery cost is consumption based. Under the current model it assumes that all power lines currently in place or ever built are required regardless of the amount consumed.

[accord1999]

Originally Posted by GGG

I think the point here is they should be. If everyone used half the electricity the delivery costs would be less. It wouldn't be linear with consumption but some portion of the delivery cost is consumption based. Under the current model it assumes that all power lines currently in place or ever built are required regardless of the amount consumed.

The problem with solar is that it is intermittent, if it's sunny and in the summer it can reduce electricity demand. But if it's cloudy, then the demand comes back. You still need the same amount of distribution infrastructure and the same dispatchable electrical generation sources.

Plus, in almost all industrialized areas, peak electricity demand is in the late afternoon-early evening where solar is already weak or non-existent..

[GP_Matt]

I think that the problem is that the transmission companies are paid a fixed profit margin. If they want to make more money they have to spend more money increasing their profit.

It is a terrible incentive and can lead to some incredible inefficiencies.

[Coys1882]

Originally Posted by ken0042

Simple math. 3000 watt solar system; assume only 6 hours per day of useful solar activity means you are putting 18 kw/h of power into the grid per day. That's 540 kw/h per month.

No residential sites in YYC produce that much electricity back to the grid - 90% of the generation is immediately gobbled up by current load. Most see about 10-50 kwh per month leak back to the grid.

[ken0042]

That makes sense. I guess either way, a person using solar is either putting that power back onto the grid, or at least not consuming that power from the grid. So even if only 10-50 kwh goes back, there's still a lot of power that was not consumed.

[Coys1882]

Originally Posted by ken0042

That makes sense. I guess either way, a person using solar is either putting that power back onto the grid, or at least not consuming that power from the grid. So even if only 10-50 kwh goes back, there's still a lot of power that was not consumed.

Your estimation on the generated kwh is a bit high like others have mentioned - most sites are seeing a difference of 200-300 kwh drop in consumption when compared to usage prior to panel install.

Right now - and I'm not sure of the kind of panel being installed here in Calgary compared to the kinds available elsewhere and the generation difference between them - but it seems having them installed is more of a conservation choice as opposed to a financial one.

[bizaro86]

Originally Posted by ken0042

That makes sense. I guess either way, a person using solar is either putting that power back onto the grid, or at least not consuming that power from the grid. So even if only 10-50 kwh goes back, there's still a lot of power that was not consumed.

Solar is definitely great, and the comments about motor start up loads (which I think is where the beer fridge comment came from, obviously could have been better put) only really apply if you were going to go off grid, which doesn't make much sense if you live in a city.

I'd love to see the transmission charges become variable, because it would provide more incentive for conservation and things like solar. After all, not consuming power at your house has exactly the same effect as adding generation right where the load is, no transmission required. Under the current pricing, (where solar is around $2/watt installed) it's either something you can justify economically if you can cobble together a system and install it yourself, or you're doing it for lifestyle/green reasons as opposed to economics, which isn't that sustainable.