131–140 of 143 posts
I think this is a fascinating argument and makes sense. However, Is the EEI really someone we trust with a report like this? It seems - given their position - they have a lot to gain and little downside in trying to scare what are essentially politicians into helping protect them. Perhaps that's why the media ignored this report to begin with?
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Excuse my ignorance (I am a layperson and simply interested in this subject), but are you suggesting that the utility themselves would rollout distributed solar to their customers, and thus the utilities engineers are skeptical of the technology and how it would be rolled out? It seems to me that the whole point is that consumers will begin the rollout themselves, generating and storing power on their own and the onl…
I think the article is talking about customers who buy their own solar installations. The thing is, no system is available (afaik) that is 24/7 solar power (batteries add a massive cost to user solar installations) so the only way for you to have power at all times is to sell the surplus generated solar back to the utility (which is where the engineering problems come in) during peak solar hours and using the gird of…
SolarCity will install a bank of Tesla Motors Li-ion batteries for grid backup and load shifting. This would be financed over the course of the loan (typically 20 years), not all at once. http://www.solarcity.com/residential/energy-storage.aspx
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> Don't even consider solar panels until you've reduced energy needs first. Absolutely, asynch13! That's what I did. It took over two years, starting with a home energy monitor. Using a home energy monitor such as [1] or [2], one can get frequent measurements, every six seconds for [1], then identify individual loads by switching them on and off during a period of otherwise steady demand. Other loads silently switch…
They charge you for feeding excess power back into the grid?
* My utility (Los Angeles DWP) accumulates a 'dollar banking' credit for the present value of net energy [signed power flow integrated over the two-month interval of my utility's billing period] fed back to the grid when a billing statement period is net-energy-productive (i.e. the PV system made more energy than my home consumed over the statement-period of two months). I pay a $22 'minimum charge' (normalized: $11/mo) for, as I see it, my share of utility equipment amortization and operations I'd otherwise be paying as a consumer. Fair enough: I do draw energy when the sun goes down. It's co-operative.
* In the summer, my 5-ton A/C use exceeds my PV system's production capacity; I become an energy consumer during one or two billing periods. My utility calculates the price for the _net_ energy I use per period, then debits the 'dollar banking' account. If that gets exhausted, then I pay the residual, otherwise my 'dollar banking' balance just goes down.
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> Not to mention lumen per dollar increase rate of LED lighting The energy efficiency of LEDs still doesn't beat CFL, except for really really expensive LEDs.
> The energy efficiency of LEDs still doesn't beat CFL, except for really really expensive LEDs. Not at all! CFLs cost $1.74 per bulb with an efficacy of 64 lumens/watt [1]. LEDs cost $12.47 per bulb with an efficacy of 84 lumens/watt [2]. As far as LED bulbs go, $10-$15 per bulb is a pretty typical price. A more correct phase is "The average LED is 30% more efficient than a CFL, but costs 7x more." Anyway, both halv…
Congratulations: You found an example of a really really expensive LED - which is exactly what I said.
And I've seen this LED before - it's the very first one I've ever seen that beats a CFL for efficiency, and it does it by having a CRI of 80 (the legal minimum). So the color advantage LEDs have over CFL? Not for this bulb - this bulb looks terrible, so bad that it's going to turn people off from LEDs, the same way the early bad CFLs made people think they are all bad.
How exactly are you saving anything from flexibility? Who cares if they are dimmable, the majority of the time you don't, and the tiny savings in electricity when you do hardly matter.
I turn my CFLs on and off quite often and I go years between having to replace them. And they cost 74 cents - replacing them is hardly an expensive proposition even when they fail (which they usually don't).
Check the efficiency of LEDs that cost no more than $5 (still 6x the price of a CFL, but reasonable) for around 800 lumens, if you find one that beats - or even matches - a CFL let me know. And make sure the CRI is comparable too. A low CRI CFL is also much more efficient.
Haizt's Law has nothing to do with efficiency. Also, the theoretical max for efficiency is 250 lm/w. It's going to get much much harder to improve things as we get closer.
I agree that eventually LEDs will beat other technology. It's just not there yet.
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LOL talk to an EE about the orders of magnitude involved, you're not going to like the answers. The cheapest storage battery is simple lead acid figure a quarter per watthour installed. Or a KWh is $250. But with a 100% charge/discharge cycle the battery will be dead and need replacing in about 10 or so cycles. To get up to 1000 or so cycles (which is only 3 yrs daily cycles) means you only get to use about 10% of th…
Also, you are off by a factor of 1,000 on your capacity. $50 billion / $2500 implies 20 million kilowatt hours, which is 20 gigawatt hours.
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> The only difference to them is that you draw less power than you used to. That is not the only difference; the pattern of your load changes too. With 100% grid-supplied power, changes in load are driven by slow-moving, predictable systems like sunrise/sunset, weather, and seasons. If you are running your own solar array, though, you will vary your grid load on much shorter time scales unless you invest in a big bat…
With 100% grid-supplied power, changes in load are driven by slow-moving, predictable systems like sunrise/sunset, weather, and seasons. If you are running your own solar array, though, you will vary your grid load on much shorter time scales I'm not so sure that these latter variations are significantly less predictable than what you mention in the former paragraph. Isn't the output of a solar array dependent on the…
The issue is that the supply side and supporting infrastructure is built for an entirely different system where power leaves the power plants and goes through the grid to consumers. Now people are adding solar panels which generate a ton of electricity during the day (when everyone is largely at work/school) that must then be fed back into the grid, opposite the direction of normal flow.
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> The energy efficiency of LEDs still doesn't beat CFL, except for really really expensive LEDs. Not at all! CFLs cost $1.74 per bulb with an efficacy of 64 lumens/watt [1]. LEDs cost $12.47 per bulb with an efficacy of 84 lumens/watt [2]. As far as LED bulbs go, $10-$15 per bulb is a pretty typical price. A more correct phase is "The average LED is 30% more efficient than a CFL, but costs 7x more." Anyway, both halv…
First, a arithmetic error: it's $0.74 per CFL, not $1.74. So so the LED costs 17x as much as the CFL. Congratulations: You found an example of a really really expensive LED - which is exactly what I said. And I've seen this LED before - it's the very first one I've ever seen that beats a CFL for efficiency, and it does it by having a CRI of 80 (the legal minimum). So the color advantage LEDs have over CFL? Not for th…
Sorry, what? The linked four pack of CFLs costs $6.97. You must have been doing some very interesting taxes this week if you think 6.97 / 4 = 0.74. (Apologies if you are not American.)
> Check the efficiency of [800 lumen] LEDs that cost no more than $5
They don't exist. Even cheap direct-from-China LED bulbs* are more expensive than that. $10-$15 per bulb is the typical cost and you'll be hard pressed to find 800 lumen (60 watt equivalents) for any less. I'll gladly check their efficiency if you can show me where to get that many lumens for that price.
* Actual lumens. Many Chinese reseller sites will outright lie and you need to check the manufacture's website. Eg, http://dx.com/p/193927 says 1008 lumens while http://www.sencart.net/e27-24smd-5060-led-pure-white-lights-... says 700 lumens.
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LOL talk to an EE about the orders of magnitude involved, you're not going to like the answers. The cheapest storage battery is simple lead acid figure a quarter per watthour installed. Or a KWh is $250. But with a 100% charge/discharge cycle the battery will be dead and need replacing in about 10 or so cycles. To get up to 1000 or so cycles (which is only 3 yrs daily cycles) means you only get to use about 10% of th…
Using the battery tech that is so cheap you can only 10% discharge sounds.. suboptimal.
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First, a arithmetic error: it's $0.74 per CFL, not $1.74. So so the LED costs 17x as much as the CFL. Congratulations: You found an example of a really really expensive LED - which is exactly what I said. And I've seen this LED before - it's the very first one I've ever seen that beats a CFL for efficiency, and it does it by having a CRI of 80 (the legal minimum). So the color advantage LEDs have over CFL? Not for th…
> First, a arithmetic error: it's $0.74 per CFL, not $1.74. So so the LED costs 17x as much as the CFL. Sorry, what? The linked four pack of CFLs costs $6.97. You must have been doing some very interesting taxes this week if you think 6.97 / 4 = 0.74. (Apologies if you are not American.) > Check the efficiency of [800 lumen] LEDs that cost no more than $5 They don't exist. Even cheap direct-from-China LED bulbs* are…
That is very very interesting, for me the price is listed as $2.97. I can post a screenshot if you like.
I'm wondering if it might be because there are utility rebates in my area, and my local store has a lower price.
> They don't exist.
I figured. I don't think the time for LED replacement bulbs has come yet, but we're getting there.
Although I am considering this fixture http://www.ebay.com/itm/170922117326 for a new installation because once I include the costs of the hardware the price is a wash, and LEDs are much better for outdoor use.
I do hope they are not lying about the lumens though.
I think LED specific fixtures are going to be a much better choice for now, rather than edison base bulbs.
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Using the battery tech that is so cheap you can only 10% discharge sounds.. suboptimal.
You could probably store and recover more energy from those batteries by lifting them from a crane.