3 ms·

Not at night it isn't. High costs for storage mean that photovoltaic solar will need to be complemented by other sources for a good while yet.

by tjmc 15y ago

ScotterC 15y ago
It's funny. If storage costs drop then everything improves. Hydro would become amazingly useful cause you could run the dam all the time and store the energy in batteries. The biggest problem with power generation is the fluctuation of starting and stopping the plants. Solar would not be a sole beneficiary.
- hyperbovine 15y ago
  You can store energy in a dam. Pump it up during the day, run it through the turbines at night. Probably not too efficient but lack of storage is not a convincing reason for giving up on renewables, IMO.
  - tambourine_man 15y ago
    “Water in lakes has ~300k cubic kilometers ~ 3 * 10^14 kg http://ga.water.usgs.gov/edu/earthwherewater.html http://ga.water.usgs.gov/edu/earthwherewater.html Potential energy is ~ 9.81weightheight Storage requirements (USA): 336 billion kWh = 1.2 10^18 J height = 1.2 10^18 / (9.81 * 3*10^14) kg ~ 408m We would need to pump water in all lakes about 408m high to have 7 day worth of reserves for USA.” http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-battery/#comment-194 http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-bat...
    - Inufu 15y ago
      Actually, that's wrong by three orders of magnitude. One cubic km has 10^9 cubic meters. Each cubic m has 1000 kg of water, so one cubic km has 10^12 kg. If you now have 300k cubic km, that's 3*10^17 kg. So you actually only need to use 0.1% of all lakes.
- stephenhalter 15y ago
  Like the sibling comment by hyper bovine mentions, you can store energy behind a dam. http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity
krschultz 15y ago
Energy usage at night is far smaller than during the day, so much so that we have an excess at night because of all the plants with constant output. You can tell just by looking at how the power companies charge industrial customers. On a residential scale, they bill you per hour. On an industrial scale there are contracts negotiated and a big component of that is what time of day the power is used. Ski resorts run thousands of HP in water pumps and air compressors to make snow, and they do it at night mostly because they all have power contracts with lower prices at night. Efficiently moving power from one place to another is the big problem - the 'smart grid' is forever over the horizon - but storage only becomes a big problem after we have switched a massive amount of our energy production to solar and we're a long way off from that. Until then we just need to build a better system to move power from constant output plants to areas served by transient power sources.
- anamax 15y ago
  > Ski resorts run thousands of HP in water pumps and air compressors to make snow, and they do it at night mostly because they all have power contracts with lower prices at night. Umm, no. They do that because of customers and "night is colder". Agriculture, specifically pumping water, is an example that supports your argument. > Energy usage at night is far smaller than during the day, so much so that we have an excess at night because of all the plants with constant output. Until we start charging lots of electric cars then....
  - krschultz 15y ago
    Umm, yes. I've seen electrical rates cited on more than one occasion as the sole reason why they are not making snow 24/7 during the pre-season when they don't even have customers on the mountain. But don't take my word for it, it's published on the power company website. NY: http://www.nyseg.com/YourHome/pricingandrates/daynighrate.html http://www.nyseg.com/YourHome/pricingandrates/daynighrate.ht... VT: https://www.burlingtonelectric.com/page.php?pid=49&name=commercial_rates https://www.burlingtonelectric.com/page.php?pid=49&name=... The difference is almost 30%. And that's only the tip of the iceberg. When you look at the area around most ski hills, the mountain is sucking more electricity during snowmaking season than everyone else in the area combined. When you are that big, the power company shows up and negotiates everything. Rates, times, usage caps, etc. The mountain can afford to buy its own generators (or diesel powered pumps/compressors) so the power company has a good reason to cut them a deal, but like every negotiation both sides want something and the power company is looking for someone to buy its excess constant capacity. The relationship is so tight that the power company will call up the mountain and offer a lower daily rate based on usage elsewhere and the mountain will make snow accordingly. http://www.usatoday.com/weather/news/2006-12-10-vermont-snowmaking_x.htm http://www.usatoday.com/weather/news/2006-12-10-vermont-snow...

Not at night it isn't. High costs for storage mean that photovoltaic solar will need to be complemented by other sources for a good while yet.

by tjmc 15y ago

Not at night it isn't. High costs for storage mean that photovoltaic solar will need to be complemented by other sources for a good while yet.

ScotterC 15y ago

It's funny. If storage costs drop then everything improves. Hydro would become amazingly useful cause you could run the dam all the time and store the energy in batteries. The biggest problem with power generation is the fluctuation of starting and stopping the plants. Solar would not be a sole beneficiary.

hyperbovine 15y ago
You can store energy in a dam. Pump it up during the day, run it through the turbines at night. Probably not too efficient but lack of storage is not a convincing reason for giving up on renewables, IMO.
- tambourine_man 15y ago
  “Water in lakes has ~300k cubic kilometers ~ 3 * 10^14 kg http://ga.water.usgs.gov/edu/earthwherewater.html http://ga.water.usgs.gov/edu/earthwherewater.html Potential energy is ~ 9.81weightheight Storage requirements (USA): 336 billion kWh = 1.2 10^18 J height = 1.2 10^18 / (9.81 * 3*10^14) kg ~ 408m We would need to pump water in all lakes about 408m high to have 7 day worth of reserves for USA.” http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-battery/#comment-194 http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-bat...
  - Inufu 15y ago
    Actually, that's wrong by three orders of magnitude. One cubic km has 10^9 cubic meters. Each cubic m has 1000 kg of water, so one cubic km has 10^12 kg. If you now have 300k cubic km, that's 3*10^17 kg. So you actually only need to use 0.1% of all lakes.
stephenhalter 15y ago
Like the sibling comment by hyper bovine mentions, you can store energy behind a dam. http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity

krschultz 15y ago

Energy usage at night is far smaller than during the day, so much so that we have an excess at night because of all the plants with constant output. You can tell just by looking at how the power companies charge industrial customers. On a residential scale, they bill you per hour. On an industrial scale there are contracts negotiated and a big component of that is what time of day the power is used. Ski resorts run thousands of HP in water pumps and air compressors to make snow, and they do it at night mostly because they all have power contracts with lower prices at night. Efficiently moving power from one place to another is the big problem - the 'smart grid' is forever over the horizon - but storage only becomes a big problem after we have switched a massive amount of our energy production to solar and we're a long way off from that. Until then we just need to build a better system to move power from constant output plants to areas served by transient power sources.

anamax 15y ago
> Ski resorts run thousands of HP in water pumps and air compressors to make snow, and they do it at night mostly because they all have power contracts with lower prices at night. Umm, no. They do that because of customers and "night is colder". Agriculture, specifically pumping water, is an example that supports your argument. > Energy usage at night is far smaller than during the day, so much so that we have an excess at night because of all the plants with constant output. Until we start charging lots of electric cars then....
- krschultz 15y ago
  Umm, yes. I've seen electrical rates cited on more than one occasion as the sole reason why they are not making snow 24/7 during the pre-season when they don't even have customers on the mountain. But don't take my word for it, it's published on the power company website. NY: http://www.nyseg.com/YourHome/pricingandrates/daynighrate.html http://www.nyseg.com/YourHome/pricingandrates/daynighrate.ht... VT: https://www.burlingtonelectric.com/page.php?pid=49&name=commercial_rates https://www.burlingtonelectric.com/page.php?pid=49&name=... The difference is almost 30%. And that's only the tip of the iceberg. When you look at the area around most ski hills, the mountain is sucking more electricity during snowmaking season than everyone else in the area combined. When you are that big, the power company shows up and negotiates everything. Rates, times, usage caps, etc. The mountain can afford to buy its own generators (or diesel powered pumps/compressors) so the power company has a good reason to cut them a deal, but like every negotiation both sides want something and the power company is looking for someone to buy its excess constant capacity. The relationship is so tight that the power company will call up the mountain and offer a lower daily rate based on usage elsewhere and the mountain will make snow accordingly. http://www.usatoday.com/weather/news/2006-12-10-vermont-snowmaking_x.htm http://www.usatoday.com/weather/news/2006-12-10-vermont-snow...