prius Archives - GreenMonk: the blog

Toyota Prius and Honda Insight – Spot the difference?

July 14, 2009 by Tom Raftery

I went to Jerez today to collect the a Honda Insight which Honda offered to me to try out. They are letting me have it for a week.

Jerez is about 100km away. I drove there in our Prius and drove back in the Insight. A couple of differences struck me straightaway –

First off, the dashboard of the Prius is far clearer – the Insight’s dashboard is not integrated and makes finding the information you want more complex (not something you want distracting you while you are driving)
Secondly, the Insight seems more responsive than the Prius – although I wasn’t pushing the Insight, the accelerator was very obviously more sensitive than the Prius’.

In terms of fuel economy, the Prius beat the Insight on the 100km journey with the Prius achieving 5.1l/100km as opposed to the Insight’s 5.5l/100km – it might not sound like much but that makes the Prius 8% more fuel efficient than the Insight in this (admittedly unscientific) test.

I’ll publish more pics and impressions of the insight as the week progresses.

Better Place to charge US$0.08 per eMile

April 28, 2009 by Tom Raftery

I have been a fan of Better Place and their unique model around electric vehicles since I watched Shai Agassi’s presentation at the DLD conference in January 2008.

If you are unfamiliar with the Better Place model, they looked at the idea of electric vehicles and people’s ‘range anxiety’ and asked how best to solve it. Their plan, put charging stations anywhere people park and build cars (or have a partner build cars) with readily swappable batteries, so if you are traveling beyond the range of the battery in your car, you drop into a swap station when your battery starts to be depleted, swap batteries and drive on. Simple!

In the Better Place business model, Better Place owns the battery in your car and charges you for the energy your battery uses – similar to how a mobile phone company charges you for minutes talktime.

Being a fan of the Better Place model I watched Shai’s talk at the TED conference earlier this year with great interest and he didn’t disappoint. A very inspirational talk. Until you start to do the maths!

Shai mentioned a price of 8c per mile (in the US) for driving a Better Place car. Frankly this sounds expensive to me.

I filled the tank in my car yesterday and took a note of the price. It was €0.948 per litre. Now my maths are not the best so bear with me while I work through this (and please do point out any errors in the comments – I want to be proven wrong on this!).

I use 5.1 litres per 100 km in my car so to drive 100km costs me €4.8348 (5.1 x €0.948).
This is €0.048 per km (€4.83/100).
This is €0.077 per mile (€0.048/.625).
This is US$0.10 per mile at today’s currency conversion rate.

If my current miles are costing me US$0.10 per mile and Shai is offering miles at US$0.08 it is not a hugely compelling case he’s making!

Now in fairness to Shai, I drive a 2008 Prius and the 5.1L/100km is roughly equal to 46mpg (using US gallons) which is about as good as you are going to get (esp as that figure is an average of urban and long-distance driving, not the maximum achieved on long-distance).

Still, for me, Shai’s 2015 figure of US$0.04 per mile is far more compelling than the 2010 US$0.08.

How much do you spend per mile and is US$0.08 attractive to you?

Electric cars are cheaper and faster than any hybrid on the market (funtoosurf.com)
Shai Agassi: eMile’s and Electric Cars (whiteafrican.com)
The Green Issue: Batteries Not Included (nytimes.com)
Better Place Electric Cars (neublack.com)
Ontario to roll out Better Place car charging infrastructure (greenmonk.net)

A giant distributed battery for the country?

July 22, 2008 by Tom Raftery

Photo Credit geognerd

Having just taken delivery today of my Toyota Prius and having just read the Rocky Mountain Institute’s (RMI) fabulous report on Vehicle to Grid possibilities, I decided it was time to address a post to this topic.

First off, what is vehicle to grid? Vehicle to Grid (or V2G) is the idea that plug-in hybrid vehicles (PHEVs) could be used to help stabilise electrical grids by consuming power when there is an excess of electricity, and selling electricity back to the grid when electricity is scarce.

The supply of electricity is variable. All the moreso as the concentration of renewable sources added to grid increases. When this variability of supply is combined with the constant variability of demand the result is an extremely unstable grid and the occasional resultant power outage. This instability increases with the addition of more renewable sources (wind and solar).

Early on summer mornings (2am to 6am) is the typical trough of demand for electricity. As more and more wind farms are added to the grid, if there is a steady wind blowing at this time, there is a very real possibility that the amount of energy being supplied by wind farms will exceed the demand! With an excess of demand over supply the price for electricity will go extremely low or even negative to stimulate demand. At this time, if there are a large number of PHEVs connected to the grid, they can pull down the excess power and store it. In other words, they start to act like a giant distributed battery bank for the country.

The following day, if there is little wind and the temperature is high (not unusual in summer) the supply of electricity will be low and the demand for power will be high as people turn on their air conditioning units. With low supply and high demand, electricity will now be quite expensive. At this time, it would make economic sense for PHEV owners to sell the electricity stored in their vehicles back to the grid.

Furthermore, as the RMI report put it:

Utilities sell a disproportional amount of their power on hot summer afternoons. At night, business plummets. For the utility, that means their expensive generation and transmission equipment stands idle. “Night-charging” vehicles, therefore, could be a lucrative twist on the business of selling electrons.

The National Renewable Energy Laboratory recently estimated that if half the nation’s light vehicles were ordinary plug-in hybrids they would represent a night-charging market of 230 gigawatts. That’s good news for the U.S. wind industry. In many areas, wind tends to blow harder at night, creating more energy when the vehicles would be charging.

All this requires the implementation of smart grids by utilities. These grids will be able to signal the cost of electricity (reflecting the supply and demand) in real-time and devices (vehicles, air-conditioning units, diesel generators, refrigeration plants) will respond to the price fluctuations accordingly so that when electricity is expensive, the demand will drop and supply will be stimulated to increase.

Smart grid trials are already taking place with Enel in Italy having rolled out a smart grid to 27.2m Italian residences! In the US, Austin Energy has been working on building its smart grid since 2003 while Xcel Energy announced its plans to build the first fully integrated “Smart Grid City” in the nation in Boulder, Colorado.

To get this vision to become a reality, consumers will have to be incentivised to buy PHEVs. This might be done by governments, or by utilities who contract with the vehicle owner to subsidise the price of the car, for the use of the battery when needed!

Governments could help push this forward by mandating that all government owned vehicles be PHEVs (though the police might want a derogation until there are high performance PHEVs!).

Car manufacturers also need to produce PHEVs! Toyota will bring the first plug-in Prius to market in 2009 and Renault Nissan have committed to producing electric vehicles for Israel and Denmark. With oil now at $140 per barrel and not looking likely to drop significantly in the coming years, the number of people looking to buy PHEVs will only trend upwards.

Then there are the environmental benefits of large fleets of cars not emitting CO2 for large portions of their journeys. And the resultant grid stability would enable greater penetration of wind power, producing (typically) more power overnight, just when PHEVs would normally be recharging.

What about you? If you could by a plug-in hybrid which would help stabilise the grid, increase the penetration of renewables, and allow you to sell power back to the grid, would you?

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