In Part 1, I described the potential benefits of a home based EESU. By switching from peak to off-peak electricity prices and replacing two SUV's with electric cars, I would be saving about $3100/yr assuming gasoline is $2/gal. My electrical energy costs would be around $655/yr for 19,614kWh. The next question for me is could I go completely off grid for these electrical energy needs and turn that $655/yr into $0/yr or even make a gain? To answer this question, I'm going to look at theoretical wind and solar installations to produce the energy I need. One of the challenges I've encountered in performing this research is that there is no uniform way of articulating the economic benefits of solar and wind. What I mean by this is that if you embark on some of this research yourself, you'll find tons of technical information and various approaches to understanding what your technical potential is but very little that explains how to understand the associated costs. To navigate around this problem, I'm going to break the article series into 3 parts. In this article, I will describe the required footprint of solar/wind to achieve 19,614kWh/yr. In Part 3, I will describe the costs to achieve the wind/solar footprints. I will also attempt to tie in the benefit of combining an EESU with a home wind or solar installation. As you'll see later, this makes the discussion much easier to swallow for non-technical types like me.
Solar & Wind Potential
As stated previously, for my home, I need:
19,614kWh/yr =
1634kWh/month =
53.73kWh/day
To obtain this much energy from a solar or wind installation, how big would it need to be? Besides about a billion variables, you can save yourself some time to focus in on a couple of key ones. The first one will be easy for you to understand: the amount of solar energy that strikes the earth is not uniform everywhere. (eg, Antartica vs Costa Rica). To find out the potential radiance at your proposed location, use this resource from 3 Tier Group.
http://firstlook.3tiergroup.com/
Simply type in your address or long/lat location to get a per m2 assessment of your site. Toggle the switch at the bottom right of the screen that produces output in kWh/day per square meter.
In my case, I can expect to get about 3.9kWh per square meter per day. Since I need 53.73kWh so my math is 53.73kWh/day / 3.9kWh/m^2/day = 13.77 m^2. (148sq feet). Roughly speaking, I would need a 12x12ft square of solar panels to generate 19,614kWh/yr. Great! But there's a problem. If the sun doesn't shine at night, where would I grab the energy I need at night? Set that question aside for the moment. (Variable Alert: Solar installations are of at least two types: some that track the movement of the sun and those that don't...out of scope. ). Let's talk about wind!
If you know what the average wind speed is at your location and you know how much energy you want to generate in given unit of time like a year, then Jim Green from the National Renewable Energy Lab (NREL) has a formula that will tell you how large your wind turbine needs to be to meet your goals. Here it is:
annual energy output (AEO) in KWH = 0.01328 x
rotor diameter (ft.) squared x
average wind speed (mph) cubed.
(sorry for the shift out of the metric system non Americans)
To learn my average wind speed in my area, I return to http://firstlook.3tiergroup.com/. Isn't this a great resource?!?!! I love it!
19,614kWhr = 0.01328 x
A ft^2 x
11.2mph
When I solve for A, I learn that my windmill :) needs to have diameter of 14 ft or 4.3m. I don't think my neighbors are going to like me much if I press forward.
In Part 3, I will examine the capital costs associated with Solar and Wind. There's a few options out there that I need to investigate and I'll end this article by soliciting any information you may have on this type of study...hopefully based on your own experience installing solar/wind generation capabilities. Just email me (eestorblog@gmail.com) or post a note in the comment section or start a forum thread.
Note: it would pretty cool if someone created a spreadsheet that makes the above calculations a bit easier to repeat.
Gm-Volt.com picked up the EEStor Trademark story. Dr. Dennis says that GM has never tested any EEStor prototypes but that GM has an open door policy on doing so.
Since we're on the topic, I wanted to add some speculation. If I had to predict which major automaker could possibly gain access to EEstor technology first, it would be Ford. Just a few haphazard comments here and there that I've caught wind of is the basis for that prediction. And my view on this predates the current auto crisis...
Here are a set of links to trademark applications for Zenn Motor Company, LightEVs and of course, EEStor. It's interesting to note the similarity of ZENNergy and LEVergy. Is this a coordinated effort for branding purposes?
EEStor
EESU
ZENNergy
Zenn Motor Company
Zero Emission No Noise
LEVergy
LightEVs
Thanks to TheEEStory.com reader GaryB for help compiling this information.
In December of 2007, EEStor Inc., working with the Austin, TX based law firm of Larson, Newman, Abel, Polansky & White, applied for trademark protection of "EEStor" and "EESU." The trademarks were approved in September of 2008. Among the trademark "specimens" offered in the application is a document referred to as "Preliminary Ceramic Battery Specifications" which appears to contain the first known EEStor released energy packaging information.
The unit offers .65kWh working at 24 volts, 20amps continuous with a charge time of 90 seconds. The package is 101mm^3 or about the size of a 1 liter bottle of water or 2 DVD cases put together. If you're trying to imagine if this is something that could fit into a wearable power vest, it could...easily. According to Bret Decelle, historian of EEStor Inc., this new finding represents the first known packaging information for an EESU providing " a usable amount of energy in a usable package." To gain an understanding of the capabilities, imagine that you have what amounts to an iGo-like external battery source connected to your laptop. On a contemporary Dell D830 laptop (or any regular laptop) whose battery life is currently around 4hrs, an EESU as described in the trademark document would give you 35 hrs of run time. Or roughly speaking 7 cross country flights without recharging. An iGo device that had various output cabling converters could keep you mobile for days under normal use. All of this would be with a 90 second charge time using a specialized charger.
Another way to think about this is that in the footprint of a slightly larger than a DVD case, you would have the energy equivalent of a modern car battery or something that weighs 60lbs reduced down to 5lbs...certainly a key advantage for anyone not to mention a warfighter.
Following Lockheed Martin's recent receipt of a patent application for a body armor garment with energy storage capabilities, the use of the phrase EESU or Electrical Energy Storage Unit has been debated as to origin and status in ordinary language. The current trademark protection ends at least part of this debate.
Many interesting questions are raised by this new revelation first among them is certainly the following: is this a specification for a Lockheed wearable power unit, a LightEVs ebike or a set of units (just under 100) which are assembled together into the 52kWh EESU destined for Zenn Motor Company?
Discussion Topic Here:
http://theeestory.com/topics/1008
Special Thanks to Bret "BretSpot" DeCelle for help with this article. His EEStor timeline can be found here:
http://www.dipity.com/EEBretspot/EEStor_Timeline
I just spoke to Craig Vanbebber from Lockheed Martin who handles communications for the group working with EEStor technologies. He pointed out to me that due to the holidays anyone authorized for further comment is not available and we agreed to try link up again next week.
He reiterated that they are not making any statements related to EEStor at this time. Secondly, he provided permission to say this:
The patent is related to another product unrelated to our rights agreement with EEStor Inc.
As for clarification of this statement and drilling into learn more, we'll have to wait til next week. But if recent history is any indication, we may learn little more with regard to EEStor Inc.
Thanks Lockheed for the update.
Another layer of EEStor mystery was removed on Dec 24, 2008 when a patent application belonging to Lockheed Martin was published via the World Intellectual Property Organization (WIPO) for a "Garment Including Electrical Energy Storage Unit." Thus, a new reason for Lockheed Martin's reticence to comment on EEStor technology has emerged: discussing it too early could jeopardize Intellectual Property Lockheed wishes to take a hold of via this and perhaps other patent initiatives.
The application goes on to describe a new form of utility garment that includes body armor among other things. Specifially, the application discusses that the electrical energy storage unit "substantially conforms to an armour plate." The plate in turn may be "contoured to better fit a person wearing armor." The application goes on to describe power redundancy in the overall garment:
Preferably, the electrical energy storage layer comprises a plurality of sections so that, if one of the plurality of sections is damaged, the other sections of the plurality of sections remain operable. Two or more sections of the plurality of sections of the electrical energy storage layer may be electrically coupled, either in parallel or in series. The body armor includes one or more connectors electrically coupled with the electrical energy storage layer and/or with one or more of the sections of the electrical energy storage layer. The electrical connectors provide access to electrical power stored in the electrical energy storage layer.
The application includes generality for a lithium ion storage unit as well as a fuel cell storage for recharging the eesu or Li battery and names Toby D Thomas and David L. Hoelscher as inventors. Die hard EEStory followers will recall that the Department of Defense Wearable power competition that took place this past summer listed Hoelscher as it's team lead. Lockheed listed this URL as it's home website.
To discuss this topic, please visit this thread started by GaryB at TheEEStory.com. Thanks Gary!
At the time of posting this article, Lockheed Martin was not available for comment.
Other Coverage:
Clean Break
Earth2Tech
Ecogeek
Treehugger
Earth blips
Stuart Sheridan
dejoe
I sat down recently to tackle the goal of gaining a better understanding of the economic benefits of having a home based EEStor EESU. I decided to focus on 3 main areas of possible payback:
1) Moving from non-electric to fully electric (or hybrid) vehicles
2) Moving from peak to off-peak energy costs
3) Introducing home based solar and/or wind energy generation
[note: there will be at least 2 parts to this article series]
The plan is to summarize my current consumption, calculate energy cost deltas and factor in capital outlays to produce overall economic benefit statements. The guiding principle of this exercise is to use as little math as possible to make a plain English, cocktail-party-type value statement for why items 1-3 would be valuable for consumers. A remote goal of this amateur study is to find a conceptual foundation upon which one could better understand the value of the EEStor EESU to businesses of various types.
Confession: my attention span often lets me down when it comes to even small amounts of basic math. Secondly, I'm not an accountant, but I can say with some certainty that this exercise will go better for you if you start by keeping separate operating vs capital costs. Bundling it all together is best saved for the last step since it builds upon having some basic concepts arranged appropriately.
Current Consumption
I started with my latest electrical energy bill to learn that for the 12 months ended Sept 30, 2008, my household consumed 16,000kWh at a cost of $1070. My house could certainly benefit from some updated windows & insulation but the analysis justifying that is out of scope here.
16000kWh/yr =
1333kWh/month =
43.84kWh/day
$1070/yr =
$88/month =
$2.94/day
To make this article more interesting, I set aside the actual energy/cost requirements of my daily commute in favor of a scenario I think may be more interesting to "people like me." Assume with me, that I have 2 SUV's each getting 15mpg and having 20 mi one way commutes (40mi round trip--yes, probably not typical).
40mi/15mpg=
2.67gal/day/vehicle x 2vehicles =
5.33gal/day.
Today, gas in my area costs $2/gal x 5.33 gal/day.
$10.66/day x 5 days/wk = $53.3/wk x 52wks/yr =
$2771/fuel costs for 2SUV's.
Switching from Gas to Electricity
If I switched to an EESU based solution (eg, cityZenn) and accept the specs offered with a 52kWh EESU, I would get 300 miles on a full charge.
300mi/52kwh=
5.77mi/kWh.
For (2) 40mi commutes, one would need 80mi/5.77mi/kWh=13.9kWh/day. At my current electrical cost, that 13.9kWh/day x .0668c/kW = $0.93. With gasoline, the 2 SUV's require $10.66/day. With electrical energy, that drops to 0.93c/day. Carry it out .93/day x 5days/wk = $4.64/wk x 52wks = $241/yr. Again, compare $2771 in fuel costs to $241 in electrical energy costs for a net savings of $2771-$241 = $2530/yr. (Additional savings comes from using off-peak electricity. See below.)
Switching from Peak to Off-Peak Electricity
In my area, off-peak electricity rates are approximately (but not quite) half the cost of peak rates. My regular household electricity requirements are 43.84kWh where as my commuting requirements were 13.9kWh.
43.84kWh+13.9kWh=
57.74kWh/day.
The cost of that much electricity is $3.86/day or $1408/yr. By charging the EESU at night with off-peak energy, the overall electricity cost reduces by half (for easy math).
$1408/2=
$704.45
Time to put a few calculations together to grab a new rough net reduction in operating costs. At peak, my house electricity is $1070/yr + $2771/yr for gasoline = $3841. By using off-peak electricity for both, my cost goes down to $655.
($1070/2)+$(241/2)=
$535+120.5=$655.
$3841-$655=$3186.
By switching from gas to electric vehicle and moving from peak to off-peak electrical energy, my operating savings would be $3186/yr when gasoline is at $2/gallon. Obviously at $4/gas, it would be a hell of a lot more.
Switching from Grid to Solar & Wind
To start the analysis of reducing my dependency on the grid for electricity, let me restate that I need 16000kWh per year for my home and 3614kWh per year for my commute for a total of 19614kWh/yr.
19,614kWh/yr =
1634kWh/month =
53.73kWh/day
----------
This is a good place to end part 1. Looking forward to feedback on what we've got here so far.
Details are still emerging but it appears EEStor Inc. was issued a US patent yesterday.
Thread here:
http://theeestory.com/topics/934