Live data from Hacker News

Who's afraid of Solar PV?

theconversation.edu.au

1–10 of 60 posts

Re: Who's afraid of Solar PV?

#3
Related:

http://reneweconomy.com.au/2012/why-generators-are-terrified...

http://grist.org/article/2011-11-23-the-problem-with-the-ren...

http://www.recycled-energy.com/newsroom/publication/the-batt...

http://www.ilsr.org/solar-grid-parity-101/

http://www.greentechmedia.com/articles/read/how-will-the-cal...

Re: Who's afraid of Solar PV?

#4
An interesting problem is highlighted on that graph: solar seems to be peaking around mid-day, but energy demand peaks at 5 - 7 pm when solar is pretty weak. The curves showing pre- and post-solar have almost identical peaks; solar hasn't yet successfully reduced peak load. (The California energy system posts a similar graph, with a similar shape: http://www.caiso.com/Pages/TodaysOutlook.aspx , made worse by the fact that the California wind farms apparently perform best in the morning and worst in the afternoon.)

The difficulty is that, unless storage gets dramatically better, we'll still need a huge conventional electricity base. And it will still burn a huge amount of fuel: most generators are not "instant-on" -- it can take weeks to spin up a nuclear plant, days to spin up a coal plant, and hours [1] to spin up a natural gas plant. Of course, there are some savings, but there is huge waste if you have to keep the whole conventional energy infrastructure spinning during the day just to fuel that 6 pm peak load.

Advice to entrepreneurs: finding a cost-effective way to store solar energy for 4 hours will be worth more than another 2% increase in efficiency. And inventing instant-on conventional-fuel plants will also make a huge difference in GHG emissions.

[1] - Page 8 of http://www.euec.com/getattachment/euecjournal/Paper_3.pdf.as... gives times between 1.2 hours for a warm start to 6 hours for a cold start.

Re: Who's afraid of Solar PV?

#5
TL:DR; version: Utilities make most of their profit during 'peak' times (noon to 5pm) and SolarPV systems are reducing the requirement during those times, putting price pressure on electricity.

Here in California we had a similar challenge but with Watar. We periodically go through drought cycles and during the last big incentives were put in place to get people to use less water, rebates for toilets, reduced cost if you were 20% below your non-drought average, no watering during the day, drip irrigation, etc etc. Then the utility needs a rate increase because they aren't getting as much water usage. It is a hard sell though to tell people "You have to use 20% less but we're going to charge you the same amount"

So electricity, like water, is a blended cost where the scarcity unit is priced to cover the physical plant costs of delivering the unit. We wholesale adoption of Solar PV it will require power utilities to come up with a different formula to recover their costs. The end result is that it will shift the cost from business (who pay the biggest power bills during the day) to non-businesses.

[1] http://sanfrancisco.cbslocal.com/2011/04/19/east-bay-custome...

Re: Who's afraid of Solar PV?

#8

A shift in energy production is good news, so now we can use our coal generation capacity to desalinate water. We get new sunlight every day, but the fresh water that we have is all we have.

"We get new sunlight every day, but the fresh water that we have is all we have." Actually, we get new fresh water every other day - it's called rain.

Re: Who's afraid of Solar PV?

#9
>> The unspoken fear of all utility managers is the “Death Spiral Scenario”.

>> In this nightmare, a utility commits to build new equipment.

>> However, when electric rates are raised to pay for the new plant, the rate shock moves customers to cut their kWh use.

We have a "death spiral" in water prices in my local (southern California) water district.

There was a drought. People were asked to conserve. People conserved too much. Drought ended. Water use did not return. Water companies then need to raise prices to meet their distribution costs. Which lowers demand further.

It can only end ugly.

Re: Who's afraid of Solar PV?

#10

A shift in energy production is good news, so now we can use our coal generation capacity to desalinate water. We get new sunlight every day, but the fresh water that we have is all we have.

You do realize that a significant portion of that new sunlight we get every day ends up producing new fresh water?
Post reply on HN