Posts Tagged ‘electric cars’

Thermal efficiency and “emissions elsewhere” from electric cars

August 30, 2016

All electric cars shift emissions from the exhaust pipe of the vehicle to the place where the electricity is generated. The actual mix of fuel sources used to feed the grid then represent the emissions profile of electric cars. The efficiency of electric cars from generation of electricity to wheel-power is not much different from gasoline based automobiles and clearly inferior to diesel engines.

Fossil fuels used directly in vehicle internal combustion engines have a thermal efficiency ranging from 37% for gasoline to over 55% for very large marine diesels.

source JSME

source JSME

For electricity generation the thermal efficiency varies from less than 30% to over 60% for coal, oil, gas, solar thermal or nuclear power plants. Thermal efficiency is meaningless (and undefined) for hydropower, wind power or photovoltaic solar.

thermal efficiency of power generation

An electric car being charged from the grid does so after a further 10% of transmission and distribution losses but only accrues a further 2 – 5% losses through the motor(s) to shaft rotation. (There are further mechanical losses in getting to the rotation of the wheels but these are common to all kinds of motive power).

The emissions due to the use of an electric car are entirely dependant upon the emissions involved in the generation of the charging electricity. If the grid is largely dependant upon coal (India), or coal and gas (US) then the gaseous emissions are higher than for diesel engines but slightly better than for gasoline automobiles. If, the grid is primarily hydropower as in Norway, or primarily hydro and nuclear (as in Sweden) then there are virtually no emissions from electric vehicles.

The fundamental reality is that electric cars are not yet commercially viable (range, weight, charging time and cost). Two decades of subsidies also confirms for me my contention, that subsidies are usually counter-productive, always delay commercialisation and nearly always lead to a focus on milking subsidies rather than commercialising a technology.

A recent Forbes article addresses the fantasies surrounding emissions, and Tesla cars. I wouldn’t mind owning a Tesla car where my acquisition price is heavily subsidised. But now that the initial investors have milked the subsidies, and operations – in spite of the subsidies – have yet to show a profit, I would not invest in Tesla shares.

Earlier this summer, SolarCity, Elon Musk’s rooftop solar company, appeared to be headed toward bankruptcy. So it shocked investors everywhere when Musk’s other brainchild, Tesla Motors TSLA -2.21%, itself struggling, announced plans to acquire the struggling panel maker and installer.

“Tesla Talks Big, Falls Short,” read a headline last week on the front page of the Wall Street Journal. The subtitle: “Car maker has failed to meet more than 20 of CEO Elon Musk’s projections in the past five years.”

Surely combining two wrong businesses won’t make a right one. True, they’re both politically correct. But they’re economically incorrect.

Tesla’s operating losses, along with its fishy accounting practices and unrealistic investor promises, have led Devonshire Research Group to liken the car company’s business model to Enron’s.

Bad entrepreneurship is normally punished by market losses and contraction. But Musk’s market is rigged. A mountain of taxpayer subsidies is allowing Tesla’s bad show to go on — and even expand.

Musk’s various ventures have received almost $5 billion worth of government assistance. Nevada recently chimed in with $1.3 billion to incentivize Tesla to build its “gigafactory” — a new battery producing facility — near Reno. Each car sold by Tesla receives a federal income tax credit of $7,500. And California allows an additional $2,500 rebate to its citizens.

Even the White House is throwing cash Musk’s way. President Obama just announced $4.5 billion in loan guarantees for electric vehicle entrepreneurs. According to the president, the money will help fill garages with EVs and make charging stations ubiquitous.

Tesla is redefining “too big to fail” as “politically correct, so bail.”

….. 

So-called zero-emission vehicles reflect the fuel-profile of electricity generation. 2015 U.S. electricity generation consisted of 33% coal; 33% natural gas; 20% nuclear; 13% renewables; and 1% oil.

Fossil fuels, in other words, have a two-thirds market share for EVs, wind and solar just 5%. Nuclear power, hydropower, and biomass, account for the remainder. …..

…..

http://www.forbes.com/sites/robertbradley/2016/08/24/investors-confront-teslas-energy-fantasy/2/#78d77bfa2bbe


 

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Going nuclear for a nanowatt battery life of 20+ years

February 28, 2014

Tritium batteries are now available commercially and can have a life exceeding 20 years (Tritium has a half-life of 12.3 years). These thumb-size batteries can produce enough nanowatt (1 nW = 10−9 watt) power to keep micro-electronics going. An 8-bit PIC microcontroller chip when in “sleep” mode consumes around 10 nW. The cost is still in thousands of Dollars but should come down fast. It appears that they could be scaled up to the microwatt (1 µW = 10−6 watt) range which would be enough to power a wristwatch.

Commercial nanoTritium battery by City Labs

Commercial nanoTritium battery by City Labs

Tritium (symbol T or 3H, also known as hydrogen-3) is a radioactive isotope of hydrogen. The nucleusof tritium (sometimes called a triton) contains one proton and two neutrons, whereas the nucleus of protium (by far the most abundant hydrogen isotope) contains one proton and no neutrons. Naturally occurring tritium is extremely rare on Earth, where trace amounts are formed by the interaction of the atmosphere with cosmic rays. The name of this isotope is formed from the Greek word “tritos” meaning “third”.

Tritium is produced in nuclear reactors by neutron activation of lithium-6. This is possible with neutrons of any energy, and is an exothermic reaction yielding 4.8 MeV. In comparison, the fusion of deuterium with tritium releases about 17.6 MeV of energy. High-energy neutrons can also produce tritium from lithium-7 in an endothermic reaction, consuming 2.466 MeV. This was discovered when the 1954 Castle Bravo nuclear test produced an unexpectedly high yield.

Gizmag reports:

(Tritium) although occurring naturally in the upper atmosphere, it’s also produced commercially in nuclear reactors and used in such self-luminescent products as aircraft dials, gauges, luminous paints, exit signs in buildings and wristwatches. It’s also considered a relatively benign betavoltaic, providing a continuous flow of low-powered electrons for a good many years.

According to the Environmental Protection Agency, tritium has a half-life of 12.3 years and the Model P100a NanoTritium betavoltaic power source from Toronto’s City Labs is claimed to be capable of providing juice to low-power micro-electronic and sensor applications for over 20 years. It’s described as robust and hermetically sealed, and the tritium is incorporated in solid form.

Independent testing undertaken by Lockheed Martin during an industry-wide survey also found the technology to be resistant to broad temperature extremes (-50° C to 150° C/-58° F to 302° F), as well as extreme vibration and altitude.

Examples of possible applications for the technology offered by City Labs include environmental pressure/temperature sensors, intelligence sensors, medical implants, trickle charging lithium batteries, semi-passive and active RFID tags, deep space probes, silicon clocks, SRAM memory backup, deep-sea oil well electronics, and lower power processors.

It is still a long way from microwatts to the kilowatts needed to power a home or to drive electric vehicles and the Megawatts needed for small scale power generation. Central power generation requires Gigawatts.

It is easier to convert nuclear radiation into heat and only some materials are betavoltaics which generate current. If only all low-grade radioactive waste from nuclear plants could be converted into batteries! Perhaps nuclear batteries are the breakthrough that electric cars are waiting for!! With current battery technology they are not going anywhere very fast.

Fisker Karma electric hybrid car is a gold-mine – for someone

August 20, 2012

As Fisker recalls all its Karma cars because of a fire risk, I observe that it represents yet another case of the fundamental failing of subsidies.

1. Fisker has received government subsidies of $528million

(more…)


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