Thursday, March 12, 2009

The obstacles to Alternative Energy implementation are in our heads. Are they?

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!

7 comments:

Berkeley Nation said...

Great ideas and enthusiasm permeate your post ! Wind tends to be intermittent in nature and thus cannot be estimated this easily. I bet for each section of the country there are kwh/year estimates that would help one properly size their wind system.
Keep up the great posts!

Sanjoy Sanyal said...

Sami

great ideas and great enthusiasm. having said that I think it is going to be sometime. I run an online advocacy site on cleantech and sustainability www.regainparadise.org and we are developing educational material on the various technologies out there.

I am no expert on this myself but here are some broad comments:

1. In solar there are too many competiting technologies out there and it is not clear which will win out at the end of the day (pun not intended)
2. In wind, the economics of small wind turbines is not necessarily viable.
3. Finally, as you observed cleantech requires policy support and government policies across the world are yet to achieve stability.

That having said, I am an optimist otherwise I am not here:)

Anonymous said...

There are many fine technologies available now. The real problem is that you have a global economic system that is built upon the fossil fuels. Everyone, you and I included, is vested in that system. Until that system begins to either show signs of resource scarcity or danger to the public health then most people will stick to what they know. The irony is that with the melting ice caps, there promises to appear vast new oil fields in the arctic regions so it seems unlikely that we will be experiencing oil scarcity soon. Coal continues to be plentiful around the world. Natural gas, when one considers the vast quantities of untapped methyl hydrates, will be around for many decades. On the public health side, the interaction between fossil fuels and public health is often too oblique to be seen as imminent. So the end result is the status quo for a long, long time (with a small amount of futuristic research and implementation). Still I encourage you and everyone else to keep working on ways of making the world a better place for our grandchildren's grandchildren.

Kerinia said...

Sami -

Great blog, and good questions.

I have one tweak to your numbers and one suggestion for your readers.

Your solar numbers are not quite right, solar uses more than 5 hours of sun. The "typical" PV system getting installed these days is about 2kW, which go for about $14,000 to $16,000 (pre incentives) depending upon location.

The main objection that homeowners express is the lack of resale value. No one expects to be in a home for 20 years, and homeowners generally are not able to recover their investment, therefore they are not installing systems.

The city of Berkeley was the first to recognize this problem and implemented a process for homeowners to get a loan which is paid back via property taxes (google the "Berkeley Model Property Taxes") to learn more.

Kerinia Cusick
www.syn-dex.com

jpouchet said...

Sam,

Nice enthusiasm but for a finance person horrible math. Those who live with wind power know that 20 years is a 3 to 5x life-cycle for many of the major components in a wind turbine. Secondly the minimum wind-speed you noted is just that - a minimum to get the blades spinning to overcome internal friction and generate some marginal power. Full power for a 3.5 kW turbine of the price range you noted, and that is certainly a very cheap unit of questionable physical integrity and most likely not a candidate for direct grid connection, does not come until the wind speed is at least 2X the minimum. This significantly reduces the practicality for wind. Not to mention HOAs have a heart attack at the thought of wind power.

For solar the news as you noted is much worse. One is ALWAYS better with today's available technology to invest in energy efficiency and conservation.

Given your energy hog model home I can easily envision slashing the use of energy from your 31.5 kW/day easily in HALF without breaking a sweat and no impact on lifestyle required. That can be done with tax incentivized dollars yielding a 30% single-year before tax return. The reduced energy consumption is a permanent cash flow savings that can be invested conservatively.

For most grid connected homes with price of electricity below 25 cents kW one is better off by taking any proposed funds for solar/wind and using ¼ to ½ for energy efficiency and conservation measures – insulation, CFLs/LEDs, ENERGY STAR ™ appliances + HVAC, windows, doors, weather stripping, water heater, etc. – which can be done over two years and still receive excellent tax credits and then investing the balance in a conservative fund. Those two moves – energy efficiency and invest the balance – will provide a net positive cash flow that will offset any potential future energy price increases for the life of the home.

THEN – when Solar and/or Wind power becomes commercially viable one can decide to yank their funds from the investment and go “green”. The cost of the system will be significantly less (ideally 10X your initial budget) in part due to the greatly reduced need for power.

But until we see solar being installed at $2.50 a watt or less -

In order to make consumer/residential level solar PV financially viable we need a national policy that:

1. Establishes either a fixed rebate schedule of $5 per watt declining 1 for 2 based upon a total installed cost starting at $10 per watt. (ie - $8/W installed nets a $4/W rebate) or a guaranteed five-year simple payback based upon individual consumer’s previous two-year average cost per kW and estimated net annual production
2. All solar PV installations are exempt from sales tax
3. All solar PV installations are excluded from the building property tax basis
4. Establish a local - State, County, City, Municipal ten-year bond funding program for Solar PV, Wind, small-scale Hydro, and Natural Gas refueling infrastructure with bonds being sold at 4% and funds made available at 5%. (this provides a positive cash flow to the agency for a change!)
5. Enable all such funds used in 4 above to be repaid via a ten-year property tax levy on the property where the assets are permanently attached.

Without the above there is no way we will see a million rooftops of PV in less than 10 years.

Sam, keep up the great blogs! Your energy and enthusiasm are driving positive change.

Shalom.

Jack

Poly Endrasik said...

I am no green tech expert (working to get in the field) but always wanted to have an off-the-grid place out in the country. My thought has always been to have wind / solar power, when available, to power the house and pump water into tanks in the attic. This would be used to supply gravity-pressure feed water to the house.
I was also going to experiment with ground level solar hot water panels (maybe wood stove boiler too) and thinking natural convection would move the hot water to the attic tanks and cold water naturally flows down - like the first Ford Model "T"s, a water/coolant pump was actually an option back then! High technology going back to the basic.

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