ROCKMAN wrote:Z - And it looks like we're on the verge of proving the commerciallity of grid scale battery storage in Texas not only for wind but also solar. As you pointed out rooftop residential solar has a limited impact compared with commercial electricity consumption. If the intermittency problem with solar is in the process of being eliminated and solar continues to get cheaper we have the room to build hundreds of commercial scale solar fields on the hundreds of thousands of sun drenched and rather cheap scrub lands in south Texas.
...nearly 20 MW of battery storage at Texas wind farms
...converting a 36-megawatt battery system at its wind farm in West Texas
...to construct a 20-megawatt, lithium-ion battery project in Dallas
Who would have thought that - batteries have become sexy. But as much as everybody loves them, none of the news clippings you quoted named the storage capacity of these projects, only their maximum power. But the Source of All Wisdom knows, of course:
https://en.wikipedia.org/wiki/List_of_e ... e_projectsSort by capacity. The largest battery storage project (the list might be a tad out of date, but it's good enough for the purpose) has a capacity of 75 MWh (25MW x 3h). That's the power supplied by one utility-scale, steam-fired turbine in about 5 minutes. These storage projects exist to stabilize the grid, not provide anything that comes even close to a significant percentage of demand. Every plant that has some significant storage capacity is pumped hydro.
Here's a good overview of current storage capacities, techs and projects:
http://world-nuclear.org/information-li ... orage.aspx"Relatively few places have scope for pumped storage dams close to where the power is needed, and overall ‘round-trip’ efficiency is 70 to 80%, but pumped storage has been used since the 1920s and today about 150 GW pumped storage is installed worldwide, including 21 GW in the USA and 38 GW in Europe. This amounts to some 500 GWh able to be stored – about 95% of the world’s large-scale electricity storage in mid-2016, and 72% of that capacity which was added in 2014. The International Energy Agency's World Energy Outlook 2016 projects 27 GW of pumped storage capacity being added by 2040, mainly in China, USA and Europe. The scope is limited by suitable sites."
...
"A World Energy Council report in January 2016 projected a significant drop in cost for the majority of energy storage technologies as from 2015 to 2030. Battery technologies showed the greatest reduction in cost, followed by sensible thermal, latent thermal and supercapacitors. Battery technologies showed a reduction from a range of €100-700/MWh in 2015 to €50-190/MWh in 2030 – a reduction of over 70% in the upper cost limit in the next 15 years. Sodium sulfur, lead acid and lithium-ion technologies lead the way according to WEC. The report models storage related to both wind and solar plants, assessing the resultant levelised cost of storage (LCOS) in particular plants. It notes that the load factor and the average discharge time at rated power is an important determinant of the LCOS, with the cycle frequency becoming a secondary parameter. For solar-related storage the application case was daily storage, with six-hour discharge time at rated power. For wind-related storage the application case was for two-day storage with 24 hours discharge at rated power. In the former case the most competitive storage technology had LCOS of €50-200/MWh. In the latter case, levelised costs were higher and sensitive to the number of discharge cycles per year, and “few technologies appeared attractive."
That's the kicker: "Battery technologies showed a reduction from a range of €100-700/MWh in 2015 to €50-190/MWh in 2030". €100-700 per MWh is 10-70 eurocents per KWh. IIRC electricity sells for an average of 9 cents/KWh in Texas.