Everybody is talking about how the economy is affecting the inertia of Greentech by (a) limiting investment and (b) having to compete with lower fuel costs
I believe that we are closer to implementable solutions than what most people think and I will try to make the calculations to prove this point. Please feel free to correct me wherever you think I might be wrong (I am no expert on this specific subject).
The average home in the US consumed 936 kWh per month in 2007 (according to the US Department of Energy), that represents $99.70 spent per month in electricity ($1,196.40 per year).
If we were to buy an alternative energy technology we could spend in that technology the equivalent capital for which annual payments equal $1,196.40 (for interest and principal – mortgage style)
Let’s assume we can get a loan at 4% for 20 years. The capital for annual payments of $1,196.40 at 4% over 20 years is $16,259.47 (at the end of 20 years the debt will be zero).
Now, let's see what we can afford with this money!
Perhaps we could buy a wind turbine. In order to calculate the capacity (and the cost) of a turbine able to cover 100% of our energy needs we need to bring the monthly kWh into a 10 hour day wind energy production. Therefore, 936 kWh divided by 30 days gives us 31.2 kWh per day. We then divide by 10 hours and obtain 3.12 kWh (per hour). In short, we need to generate 3.12 kWh for 10 hours every day to cover 100% of our electricity needs (this is achievable in almost any state with wind turbines that have a 5 m/s or 11MPH minimum wind capacity)
After a lot of web searching I found that the cost of a 3.5 kW wind turbine runs around the $12,000 mark (installed). There are additional charges for maintenance, but the "extra" $4,259.47 (remember we had $16,259.47 as total capital available) should more than suffice for those expenses.
An alternative for the wind turbine is solar power. In this case we need to convert the 31.2 kWh per day into 5 hour days of sun. Therefore, we need 6.24 kW solar panels tied to the grid (31.2 kWh per day divided by 5). According to my research these will run for around $40,000 ($23,740.53 over our budget)
But wait! We have not counted the rebates and incentives we could get from state and federal entities. I do not have enough time or energy to calculate the applicable rebates, because each county and each state and each technology has a different rebate quantity and procedure. I will risk saying that the available rebates range between 20% to 50% (perhaps making the solar panels affordable!)
Can the same principle be applied to water? Could we start by calculating the cost of water and sewer in a typical house and then find technologies that could replace either the water sourcing or the waste water removal service? The answer: I don’t know (perhaps I will explore this in a future article)
Some of the comments I got from last week's Energy Storage:
"I believe pumped-storage hydroelectric has and is being used. I remember Northfield Mountain in Massachusetts being the first that I had ever seen. Here's a Wikipedia link describing the technology and current sites using it: click"
"The gravity part is the easy part, I suspect. You will need to either find a natural land formation where you can store the water, OR, you will have to build a vessel. Perhaps that is the hidden cost. Also, you have to consider the efficiency of the system... First the primary renewable energy source cost and efficiency, then the pumping uphill efficiency, and finally, your hydro-electric generator efficiency -- that is a lot of steps and the overall efficiency, which is multiplicative, perhaps turns out to be dishearteningly low."
"This approach was implemented in Bath County, Virginia back in the 70's. It apparently worked quite well. However, it was implemented to utilize the electricity produced by coal fired turbine plants who produce a steady stream of power by day and by night, but where consumption was lower at night. So, they kept the plant at the same production level at night and used the electricity to pump the water back up the mountain above the hydro electric plant."
"The pumped hydro system suffers when you increase the scale. As the volume of water increases, the system becomes more expensive"
"That is what is being planned for Norway where there is a large hydro power industry - they are looking at having offshore wind turbines working continuously to drive pumps to release the power for peak shaving in Europe thru interconnectors."
"Last weekend I heared about a Spanish project were they haul up on a slope an 80 ton heavy concrete block when the wind was blowing, letting it make electricity when there was no wind! It is like the old clocks were you wind up the weight every day"
" It only makes sense when there are significant elevation changes, and most solar and wind farms are in the flat lands"
"1 cubic meter at the top of a 100 meter tower has a potential energy of about 0.272 kW·h for example lead-acid has power density around 100W/liter"
"A number of companies are looking at this, as well as compressed gas storage, flow batteries, etc. It looks like the maximum efficiency for pumped hydro is between 70% and 80%. Initial capital outlay for building the facility is high. It all depends on the price of fossil fuels and carbon credits..."
"Pumped hydro is severely limited in further deployment (we already have 20 GW of it in the US alone). Here's why: *Locations that have the requisite topography are very rare. *Safety issues regarding the construction of an upper aquifer at height are very real and, for the most part, insurmountable. *The politics of water make it almost completely impossible for new projects to launch. *The efficiency of pumped hydro is, at best, 78%. Batteries can achieve 85% efficiency. Right now the capital costs of batteries are far higher than pumped hydro. But placing a bet on battery prices falling due to economies of scale is smarter than placing a bet that some community somewhere will allow its water system to be interfered with."
"When I worked for an electric utility we had two pumped storage facilities that worked well but had the many of the problems indicated in previous posts. Another promising storage medium is compressed air energy storage (CAES) where air is pumped into an old salt mine (like the ones under several Great Lakes cities) and released to generate power. Like pumped hydro, the pumps turn into turbines and the motors turn into generators"
"Moving water from one place to the other in the wild raises all sorts of environmental questions. Better not done"
Until next week: SHALOM!
