Category Archives: Energy

Climate: Tried using the EPA Household Carbon Emissions Calculator and its a Fail on first Question

The first question on the EPA Household Carbon Emissions calculator is to select my type of household heating:

  1.  Natural Gas
  2. Electricity
  3. Fuel Oil
  4. Propane

We heat our home with locally produced wood pellets. Since I cannot answer the first question correctly, the entire calculator fails.

I used this one at the University of California, Berkeley and it estimates our household annual carbon emissions at about 20 tons of CO2e per year, or 62% less than the average  American home.

I used a different one in the past (link not saved) and it estimated our usage at around 16 -17 tons, and said the average home was about 40 tons/year, which seems inline with the UCB calculator.

Transportation: Do electric fire trucks make sense today?

Electrified fire trucks:

It can drive for up to 30 minutes on pure electric power, with a diesel generator for backup power.

Source: Fire Truck – Electric Fire Truck – Electric Vehicles

On the plus side, most fire trucks travel limited distances from their station to an emergency scene (by design) making them ideal for EV platforms with limited range. Of course they occasionally travel longer distances for out of district support and training.

During a fire, the truck must also power large water pumps. However, the majority of fire engine responses are not for fighting fires. When I was a volunteer firefighter, about 2% of calls were for fires, about 10%+ for vehicle accidents, and almost 90% for medical aid. Each department will have different ratios, of course.

On the negative side, the typical city fire truck averages about 5,000 miles per year:  converting to EV platforms has little impact on overall CO2 emissions compared to other options. They just don’t drive very far (by design!). By comparison, a typical large diesel semi truck used in transportation travels almost 70,000 miles per year.  Which EV conversion would have a larger impact on CO2 emissions?

(Click on image for larger view)

New ICE fire trucks appear to now cost about $500,000 and up; prices have risen rapidly in recent years due to new  safety requirements from the NFPA and that new trucks are generally larger than the vehicles they are replacing. Paying $1 million and more for a fire truck has become routine –  which seems pretty obscene but no one bats an eye because public safety.

Transportation: EV battery life

Tesla does not say how many times its batteries can be re-charged.  Since the number of charge cycles is dependent on many variable factors, that is understandable for Tesla not to provide a number. They do provide an 8-year, 90% capacity guarantee option, however.

Panasonic, which makes the batteries, citing laboratory tests (which may be very different than real world conditions) says about 6,000 cycles. An EV that drove 200 miles between charges would then see 200 x 6,000 or 1.2 million miles; the vehicle and various components would give out before that, if true.

Let’s assume half that rating or 3,000 cycles – then we’d see 600,000 miles, possibly in line with the maximum real world life of other components, and  way ahead of most vehicles on the road today. Amortizing your vehicle costs over 600,000 miles with minor maintenance (EVs need less maintenance than ICE[1]), tire replacement and so on, would provide a surprisingly low cost per mile. As noted below, this could be a very important factor in applications such as taxis which may drive 200 miles per day, every day. (And note that newer Teslas can get well over 300 miles on a full charge.)

At 200 miles/day, a car would rack up a million miles in just over 13 years. A taxi with a more normal 250,000 mile life (which is how long New York taxis last) is worn out in 4 to 5 years. If you can make the vehicle last that long, you seriously reduce the depreciation part of the robotaxi economics model and thus reduce the cost of a ride, since today depreciation is the largest cost factor in operating a car. Depreciation of the battery has been one of the largest costs of operating (and fast charging) an electric car. In fact, you can reduce depreciation so far that it becomes secondary to other costs like energy, risk, maintenance and logistics.

Source: Tesla’s Battery Guru Describes A New Cell With Massive Lifetime

Related: What causes batteries to lose capacity or fail more quickly?

From that web page leading factors in reducing capacity are:

  1. High temperatures.
  2. Overcharging or high voltage.
  3. Deep discharges or low voltage.
  4. High discharges or charge current.

Not shown, but cold temperatures reduce the operating range which can then, in turn, lead to deep discharging the battery.

There isn’t a one size fits all answer then to how many charge cycles are available in a battery. Some real world users have reported significant degradation at 50,000 miles while others have said they see minor degradation as they have passed through 100,000 or 200,000 miles. The number of cycles varies based on which EV vehicle you have, battery capacity and chemistry, whether the vehicle does effective pack and thermal management, and how the vehicle is used and how the battery is re-charged.

Nissan claims 8+ year battery life for their smaller 30 kwh pack in the Leaf. In fact, their real world data suggests much longer life, resulting in batteries being usable well beyond the life of the vehicle. This had led to suggestions that “old” EV batteries might be repurposed in a second life after the car wears out, such as in solar PV installations.

VW, meanwhile, expects its batteries will have 70% of capacity after about 100,000 miles.

[1] Tesla maintenance, which generally can only be done at a Tesla authorized dealer, is said to average about $500 per year, which is considerably less than ICE vehicles, serviced at dealers (over time). That, however, includes routine items like changing wipe blades, some fluids, light bulbs and what not, which are presumably items that the end user could elect to do themselves, saving money.

EVs, however, do depreciate faster than ICE vehicles, at least for now.

Installing a home charger can cost $1,000 and up, depending on availability of a 220 circuit and/or the need to run a long line and install a subpanel.

Energy: Lifecycle GHG emissions from a hybrid, plug in hybrid and an EV are about the same

This graphic, from the International Energy Agency, illustrates the lifetime CO2 equivalent emissions from different types of vehicles. “BEV” is a battery electric vehicle with a 400 km range, HEV is a hybrid (like Prius), PHEV is a plug-in hybrid electric vehicle.  This chart assumes the GHG emissions from electricity generation plants are in line with the global average. (FCEV is a fuel cell/hydrogen based system.)

Notably, BEVs are NOT zero emission vehicles and are, in general, on par with PHEVs and Prius-like hybrids when viewing their overall lifecycle emissions.


Source: Global EV Outlook 2019 – Analysis – IEA

The IEA’s model assumes similar sized vehicles in each category, that the EVs have a 400 km range (this determines the battery size), and that local electrical generation emits the global average CO2-equivalent for electricity generation. If the EV range were to be extended by 200 km more, add in the gray zone box above the EV column.

Energy: In many countries, hybrid gas/EVs emit lower emissions than pure electric vehicles

An average battery electric and plug-in hybrid electric cars using electricity characterised by the current global average carbon intensity (518 grammes of carbon-dioxide equivalent per kilowatt-hour [g CO2-eq/kWh]) emit less GHGs than a global average ICE vehicle using gasoline over their life cycle. But the extent ultimately depends on the power mix: CO2 emissions savings are significantly higher for electric cars used in countries where the power generation mix is dominated by low-carbon sources. In countries where the power generation mix is dominated by coal, hybrid vehicles exhibit lower emissions than EVs.

Source: Global EV Outlook 2019 – Analysis – IEA

Says the International Energy Agency.

Energy: Unplugging your cell phone charger does nearly nothing for the environment

Few people have any idea about the lifetime energy usage of popular consumer products.  50-75% of the energy and green house gas emissions for many cars occurs during manufacturing. Switching to an EV (for which much of its lifetime energy/GHGs is during manufacturing) may have little benefit to the earth.

When it comes to unplugging your cell phone charger:

Moreover, charging accounts for less than 1% of a phone’s energy needs; the other 99% is required to manufacture the handset and operate data centers and cell towers.

Source: Empty Gestures on Climate Change by Bjørn Lomborg – Project Syndicate

Energy: Over the past decade, U.S. energy predictions were way off

In 2010 the U.S. Energy Information Administration published its forecasts for 2019 on topics such as oil and natural gas production, oil imports, coal fired electricity generation, green house gas emissions and more.

And they were not just a little wrong, they were spectacularly off. For example, they predicted the U.S. would be importing over 8 million barrels of oil per day in 2019; in reality, the U.S. is a net exporter of oil in 2019. These were not small errors!

Continue reading Energy: Over the past decade, U.S. energy predictions were way off

Energy: Comparison of internal combustion engine efficiency versus EV battery packs

How many pounds of Lithium batteries do we need to replace 10 gallons of gasoline? We can calculate this out and find that we need about 1,700 pounds of Lithium-based batteries to replace about 10 gallons of fuel because of the much higher energy density of gasoline.

Read one to learn more … Continue reading Energy: Comparison of internal combustion engine efficiency versus EV battery packs

Energy: Why throwing money at climate solutions leads to no solutions

When a political leader has a choice, such as am I going to inaugurate a new solar park or wind farm, or something, and show how I care? Or am I going to spend money on some eggheads [R&D] that don’t make for good picture? The problem is the extra solar panel park is not going to do very much, but these eggheads could make a huge difference

Source: We are throwing money at the wrong solutions to climate change

I began looking at solar PV and EVs as ways to take personal action. Read my other posts about what I learned – basically, adding solar PV for some homes will reduce CO2-emissions while for others it will have not only no impact but will have spent money that will then not be available for actual CO2-emission reductions. Similarly, in some situations, purchasing an EV just transfers your CO2-emissions to the utility company and has little or no impact. And at present prices, buying an EV uses up resources that might better be spent on say, home insulation.

Longer term, we need to invest in R&D and invent new technologies. Unfortunately, we invest little in R&D while politicians are pursuing actions that have little impact. Because they do not understand what they are doing.

Energy: Should you buy carbon offsets, an EV or solar PV to reduce your environmental impact? It depends.

Some people think they should buy carbon offsets to reduce their environmental impact.

Others think that by switching to an EV, they will reduce their CO2-emissions.

And of course, some think that by installing solar PV panels, they will cut their CO2-emissions.

The reality is far more complicated. In some cases, buying an EV may increase your overall lifetime CO2 emissions especially when your electrical utility produces most or all of its electricity by burning coal and other fossil fuels. Similarly, installing solar PV panels when your utility is already 100% greenhouse free will likely increase your lifetime emissions of CO2. How? Because of the GHGs emitted during the solar PV panel manufacturing and installation and ultimately, not offsetting any GHGs because your utility is already GHG emission free.

Most people are oblivious to product’s lifetime GHG emissions, ignoring that for most products, the greatest production of GHG emissions is during the product’s manufacturing.

Continue reading Energy: Should you buy carbon offsets, an EV or solar PV to reduce your environmental impact? It depends.