World Environment - Energy Storage

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Published by Katie Stokes

Environment - Energy Storage
John S. Stokes III

Energy Storage - one of the most profound developments in the history of the human race

Our solar array (this property now sold as of August 31, 2020... will have update eventually)
Producing but not storing - Currently on net metering, effectively using the utility company as a battery
Longer term: On-site storage!


Sea levels are rising, temperatures are rising, land water evaporating at a greater rate, ice is melting, carbon dioxide is rising, methane is rising, nitrous oxide is rising, ocean acidity is increasing, coral reefs are massively vanishing, a new wave of animal species extinction and biodiversity reduction is in progress, forests continue to be cut down, the world paved over, the sea full of plastic. There is no point in hammering on the doom and gloom scene without offering solutions.

Solutions include replacing fossil / carbon based fuel consumption with renewable nonpolluting energy, reducing high water usage in food production, increasing urban densification, increasing green spaces, buying locally, many more things.

The problem with renewable nonpolluting energy sources, particularly wind and solar, is the dependency on the vagaries nature: solar works only when the sun is shining, wind power only when the wind is blowing. Fossil fuels are so convenient! The fuels can be stored and made available on demand: gas, oil, coal, uranium! Massive investments have made the extraction, refining / production, transportation and consumption of fossil fuels within the economic reach of just about everyone! Easy heat in the winter, electric illumination at night, massive highways spreading around the world, a world of technological wonders! But at great total cost when all the unintended consequences are factored in.

Wouldn't it be great if the sun and wind were available on demand?

Suddenly the game is changing. With the advent of advancing battery storage technology, wind and solar can join the game, and electric cars compete! Charge battery arrays when the sun is shining and the wind is blowing and use the stored energy at night when the winds are calm and the sky is dark! ! The cost of storing energy in battery form used to be extremely expensive. Tesla with its announcement of their massive "Gigafactory" to produce batteries has had great impact on the imagination. The primal drive to survive demands that carbon production be lowered and now a comprehensive way is emerging!

Nuclear has remained an option in some minds, as the carbon footprint there is tiny. But the risks are enormous despite the best of plans. 99.9% reliability is not enough. Already in the very short history of nuclear power, vast areas of wonderful farmland in the Ukraine are now off limits for centuries due to the Chernobyl disaster, and areas of Japan have been ruined indefinitely by the Fukushima nuclear disaster and radioactive water has and continues to leak into the Pacific Ocean. The Earth is small and these scars will last a long, long time. Then there are pools of nuclear waste all over the world, continuing to increase. There is a better way.

I am intensely interested in the concept of home and utility scale energy storage for renewably produced energy and am waiting for the prices to come down.

I foresee a great solar energy boom, a great energy storage boom, a day when "Miles per KWH" replaces "Miles per gallon"!

December 7, 2019

Three years have passed since my last update here. Battery solutions are still very expensive. Two other players have entered the scene I know about, these too are expensive.

- Tesla - Now offers "PowerWall 2". The units are not awkwardly shaped like their first generation and more powerful. Rated at 13.5KWH. Figure $10-15K to install just one. Unit cost is $6,700 uninstalled (actually more expensive than their first generation per KWH), so additional unit cost is at least that much.

- SunPower - This highly rated solar panel company now has an battery solution they call Equinox. However they do not offer their batteries separately, they are bundled with their panels. Looks like they are rated at 13KWH. Figures I've seen indicate $11K to install one, and $8K additional.

- NeoVolta - Don't know much about this company. Rated at 14.4KWH. Figure $13-16 to install just one.

If a reputable company can bring battery cost (before installation) down to $200 per kilowatt hour of stored power and they can be strung together for at least 100 KWH, I'll be a buyer!

December 19, 2016

Tesla recently acquired Solar City, a maker of solar panels. At this time Tesla is selling their PowerWall as an option with Solar City's panels and not as a "retrofit" with an existing array like mine. Tesla does plan to do so later, I await the details. Meanwhile I have not come across another company offering a product like the PowerWall.

August 22, 2016

Only little progress has been made in the direct storage of electricity in the past year.

May 12, 2015 (editing and replacing earlier posts)

On April 30, 2015 Tesla announced their battery solution for storing energy from solar arrays for use when the renewable energy is not available.

Three solutions were announced:

PowerWall 10KWH - This is a home backup battery system designed for power outages. The system is designed for a "weekly cycle". This system is no interest to me as I want to charge via solar by day, and use at night: a daily cycle. Up to 9 of these systems can be connected in a series for 90 KWH energy storage. The system is guaranteed for 10 years. Price $3,500 per battery. No inverter included.

PowerWall 7KWH - This battery system is designed for charging during the day and using during the night. Up to 9 of these systems can be connected in a series for 63 KWH energy storage. A 63 KWH configuration is close to what I want, but not ideal: the storage is not enough for charging a drained 85 KHW Tesla electric car at night plus running a house. The system is guaranteed for 10 years. Price $3,000 per battery. No inverter included.

PowerPack 100 KWH - These units are considered to be "commercial" grade. At first glance I want one! But the information is skimpy!
- Can they be charged and drained on a daily basis?
- How long is the guarantee?
- These units are described as building blocks for systems ranging from 500 KWH (5 PowerPack 100 KWH units) up to millions of KWH. Nothing announced about using just one PowerPack for home use! Can I buy just one? Again, third party inverter(s) will be required.
- No inverter included.
I have not seen the official price, have read on the web $25,000, again no inverted included.


Tesla autos are normally charged from household AC current. This means if a PowerWall battery is to be used as the energy source, the DC battery current has to be converted to AC via an inverter and then back to DC via Tesla's in-car automobile charging system. Tesla does not supply an inverter with their PowerWall battery, so the third party who installs the system will have to supply the inverter(s). As I obtain more information about inverters, I'll post notes here. Wouldn't it be a lot faster to charge Tesla's DC batteries directly from the PowerWall 7KWH batteries without first converting to AC via the inverter and then back to DC via the charging stations? I've heard that Tesla's "super charger" systems go directly from DC to DC, skipping the inverter. How much would a home based "super charger" system cost? Tesla is often compared to Apple. Apple's products do not come with missing components. Tesla should provide a complete solution: How about PowerGrid 100K batteries with inverters with daily cycling.