Palatov Motorsport dp1 EV Prototype
Engine: 60KW motor; AWD; Weight: 1,100lb; 0-60 4.2 sec; Top Speed: 100mph
Based on all the responses I got after announcing the electric project, I think some background and a clarification of project goals would be useful. In a nutshell it is this: the dp1/e is a testbed for component technologies of alternative-fueled and hybrid vehicles.
First, the main immediate goal of this project is to test the motor controller to the design of which I've made some minor contributions. We are doing this because we believe we can do better than what's currently available off-the-shelf. If I just wanted to build an electric car I might make different choices but that isn't the goal, developing component technologies is. To that end, this is really a matter of expediency - we have a motor laying around, the rolling chassis is here and it's been tested beyond the intended top speed of 120 mph. It is also low in weight and has excellent accessibility for packaging and servicing of both battery and motor.
The initial battery choice, a pack of 24 Odyssey PC680 lead-acid batteries, totaling 288V and about 4 KWh capacity at around 380 lbs weight, is also a matter of expediency and cost. Yes, I know that purpose-designed lead-acid traction batteries would provide slightly better performance but I don't know of any with which I can build a 288V pack of the size and shape I need. Even wheelchair batteries are a bit big. Likewise I'm aware of various Lithium-based batteries, ultracaps, NiMH and zinc-air batteries, fuel cells, generators and other storage and energy conversion options but I am not willing to pay the tens or even hundreds of thousands of dollars that some of those approaches require.
For reference, the 8-gallon fuel cell that I'm removing cost $400 to install, weighs about 60 lbs when full of gas, contains roughly 260 KWh of energy and costs $20 to fill. One might even get the notion that our dependence on gas is less a result of a conspiracy and more a recognition of the fact that it's an awesome energy delivery system, albeit one with significant undesirable side effects ;) Trying to do a full-function electric car using currently available batteries is a lot like trying to provide the full functionality of a modern PC while being restricted to one megabyte of RAM instead of a couple gigabytes. It's not possible to completely match the functionality but one may be able to do OK for certain applications, if enough engineering discipline is exercised.
So why would one even bother? Well, here are some personal opinions (so take them as such).
As effective as gasoline is, everyone is aware of its drawbacks by now. When used in sufficient quantities it has a large and undesirable environmental impact, from extracting the oil to its transport and processing and finally the combustion of the gasoline itself. Taking a step back and looking at the big picture, what we're really doing is using ancient sunshine that was converted to chemicals by plants and other organsims and concentrated over time into a form from which it can be conveniently extracted. Oil, along with its companions coal and gas, is what has fueled man's industrial civilization and is nothing less than the force that really eliminated slavery - which in various forms was the primary power source of all civilizations preceding ours. By its very nature this resource is finite so even setting aside the environmental harm issue, we have no choice but to find alternative sources of power - preferably ones that won't run out.
Basically mankind has not yet come up with a viable alternative to gasoline. Most new technologies, with notable exceptions of nuclear and geothermal, are focusing on making use of today's sunshine instead of millions-years-old 'bottled' kind. That is good because it is sustainable. What is often overlooked is that none of it is free, and when we do it in quantities sufficient to support a good portion of our energy use, all have environmental impact. Biofuels lead to destruction of habitat and a curious choice between driving and eating. Hydro changes landscapes and habitats. Wind and solar, while so far not in sufficient use to matter, will almost certainly have some impact if we cover deserts with solar cells and open plains with windmill forests. But they are sustainable and therefore some equilibrium of usage, environmental impact and costs can eventually be found, likely with much trial and much error. This is not an option at all for oil, long term.
This leads me to electricity - all the above mentioned energy sources can readily be converted to electricity, enabling harvesting where the energy is available and delivery to where it's needed. Electricity is the currency of energy, any form of energy can be 'exchanged' into electric power. My clients are usually not amused when I say we're really building coal-burning cars because about 40% of electricity here in Oregon still comes from coal - but it won't always be that way and it's changing every day. So electrically powered machines, be it cars, appliances, or what have you, are essentially future-proof. Whatever will end up being the great sustainable energy solution, it's a reasonably safe bet that electricity will be the means by which the energy is distributed. A great additional bonus is that due to all the advances in the semiconductor and computer industries, we now have efficient, affordable and precise ways to control electric power. Today's state of the art AC motor controllers require more processing power than even the biggest supercomputers had only 3 decades ago, but now it's available in a $15 DSP chip.
Why only a testbed/prototype?
As compelling as electric power is in theory, and as effective as it is in stationary applications, in mobile applications it faces a huge obstacle - storage. Despite much hype and allegations to the contrary, all current battery solutions are prohibitive both in initial acquisition cost and lifespan. Even a $2K lead acid pack that requires replacement after 500 charge cycles adds $4 to every charge and if you only get 20 mile range out of it (provided you stay under 30 mph it's doable), that's a twenty cent per mile premium on top of the bragged-about 3 cent direct electric cost. It radically changes the equation. Sure, an advanced technology pack can do 2K charge cycles but at $70K cost (based on 35KWh pack at $2/Wh) and let's say 100 mile normal-speed range that's a thirty-five cent per mile hit even assuming the car will actually go the full 200K miles. Sure, it'll last the life of the vehicle but the cost is still there - you still have to pay for the rest of the car, too, just as you would with a gas-powered version. That's not even mentioning the inconvenience of multi-hour recharge times. And then you have to deal with disposal/collection/recycling. I'd guess there are maybe around a million cars that are end-of-life'd every year in this country - imagine if every one had a 400 lb battery to get rid of.
So basically the storage technolgy to enable a full-function electric car at reasonable cost does not yet exist, to my knowledge (I define reasonable as near cost parity with an equivalent gas-powered car, not the roughly 3X premium and limited performance that is today's reality). Nor are we even close from what I've seen. But there is a huge need and therefore a lot of effort is being expended on trying to meet it (no conspiracy theories please, I'm still waiting to find out what happened to the 100-mpg carburetor that hasn't been matched even by modern computerized gasoline-direct-injection systems).
Electric transportation is the future. The present is hybrid systems to improve the overall efficiency by load leveling and energy recapture, and to selectively eliminate pollution in congested areas (yes even if it's by displacing it elsewhere in some cases). Both require efficient and inexpensive motors and control electronics, especially as the benefits such systems currently provide are very modest at best. So incremental cost has to be low and efficiency high. This is something that can be done now and it's something I can contribute to, so that's exactly what I'm doing.
All that said, there are some important niche markets for which today's electrics do make a lot of sense, and while in most cases they require certain sacrifices from users the benefits can be clear and worthwhile enough to justify the switch. Yes, I'm involved in some of those projects and no I can't talk about them yet. The dp1/e I can talk about.
If at some point in the development process I do end up with a complete electric vehicle that I think makes sense to sell (i.e. I would want one myself), I will be glad to do it! That's not the primary goal at the moment however.
Why dp1 chassis?
Aside from the obvious 'because it's there', the prototype chassis lends itself very well to alternative powertrains and makes an attractive test platform. It was built to answer specific questions and now that its purpose has been served, rather than retire it I just thought up some more questions to ask.