Prius as a Generator Revisited

I have yet to see any piece of modern electronics, particularly those with switching power supplies, be adversely affected or even not operate with a MSW inverter.

I wouldn't run a life support system with one but other than that, most well engineered power supplies are quite forgiving.

And standby generators are notorious for terrible amounts of harmonic distortion in the their AV waveforms. It is true that Honda does a better job than most in this regard.

I've been using these inverters, cheap and otherwise, for years without any problems.

 

I also haven't had problems with modified sine wave inverters. They've run several different laptop computers, compact fluorescent bulbs, wireless routers, and NiMH battery chargers with no problem that I could tell. A fan was a little bit buzzier, but it still worked.

Some of the better Honda gensets are actually generator-inverters rather than pure generators. That's how they get better or more stable waveforms...they have a generator put out DC power, and then use an inverter to turn that into AC.

 

Good on ya!

As I have said ad infinitum, the great hidden unspoken advantage of plug in hybirids is their ability to act as a giant battery bank for the grid. For example, we buy~15 millions cars per year. If 20% were plug in hybrids, in ten years we would 30 million battery banks parked in our driveways and parking lots. Now, using currently available affordable technology, these cars can be programmed to buy from the grid when it is cheap, and sell back when it is expensive. They could also be programmed to always retain enough charge for the days transportation need.

The advantage of this system is multifold. As to this thread, it would allow 120vac power to the house in the case of an outage (with proper transfer switches). The second advantage is a bit harder to see. All these batteries represent a HUGE reserve capacity to the grid, allowing the spinning idling capacity to be significantly shut down. (The idle reserve grid capacity that goes unused is the most expensive, the most wasteful, and the greatest useless contribution to Co2 emissions regardless of generating source, because any kwh generated but not used is 100% waste). The third advantage that goes largely unseen, is giving solar energy (PV) a 24/7 presence. The argument against solar has often been, "The sun doesn't shine at night". or "What do you do on cloudy days?". With ~30 million battery banks plugged into the grid, you now can put that solar energy into the batteries and draw it out when it is cloudy or at night. The aggregate average of sunny areas and cloudy ones would average out to a predictable average. By providing this additional reserve capacity on the grid, you can reduce further the need for peak generating capacity, with the requisite fuel and Co2 savings.

The point of this is that it begins to solve two of our biggest obstacles. The first is reducing net demand on the electrical grid, and the second is to reduce the need for oil for transportation. If solar panels were on every roof top, every parking lot,,,everywhere you could plug your car into the grid while you are at work, both to charge the car, and energize the grid. The great beauty of this system is that it uses, (for the most part) existing tried and true technology,,,,and everyone wins.

If anyone is interested in reading more about Pv and it's uses and tecnology I invite you to visit this site: Solar Electric Discussion Forum - Powered by vBulletin

It is a lively forum populated by some very smart people, most of whom have a very active interest in PV system design and installation.

Icarus

 

FWIW, one link that discusses MSW and it's possible consequences http://wholesalesolar.com/pdf.folder/Download folder/sine_modsine.pdf

Icarus is right about unused reserve capacity if one is burning fossil fuel to generate the electricity in the first place. I do get myopic living in the Pacific NW where we depend mostly on hydroelectric dams. I guess they just let water over the spillway if no one needs the power. Salmon like that

 

The truth is they don't run water over the spillway at low demand for the benefit of fish on the Columbia system. They store it for later use. LIke it or not, fish are a dead issue on the Columbia at least above Grand Coolie.

So even with hydro produced electricity there is a benefit. The power that Grand Coolie can produce is in the grid so that perhaps some fossil fuel plant in CA doesn't have to spin.

Aside from the fish, it is a win/win.

Icarus

 

Thanks. Yeah, I guess these would be the "perfect inverters", except for the price of $3k.

I presume they are TRUE sine wave.

If nothing else, this seems like an interesting route if you have a Prius and are on the fence about a DC power source, like solar or wind perhaps.

I'm afraid our solar returns aren't that great in Canada though.

 

A: True sine wave inverters are available starting at about $200. They tend to run ~ $1 per watt.
B: Canada has great solar potential in most areas. While short winter days are thought to be a problem, the truth is not always so. A little know fact is that solar panel efficiency goes UP dramatically as the temp goes down! At -20 a panel may put out ~20% above it's rated output. Additionally, reflection off o snow will have a similar effect. My best solar harvest on my off grid system is in February, as much as 50% more per day than mid summer. (I live north of Thunder Bay, ON)

For those that are interested:Solar Electric Discussion Forum - Powered by vBulletin

 

Do these new inverters have a grid independent mode? My 2001 vintage Xantrex Suntie turns off when the grid goes down. This was required to prevent backfeeding a dead grid, possibly endangering service personel who think that they are working on unpowered wiring.

 

They are still built that way. Grid tie inverters need the grid to regulate the output of the Pv array. So it serves the dual function of turning off when the grid goes down for safety as well as output regulation. Pv systems will not work well without either a battery in the circuit or the grid. Without it the current/voltage will fluctuate dramaticlly with load and sun.
Of course you can build a "hybrid" system that includes battery backup when the grid goes down, but on balance it about doubles the price of a grid connected system due to the battery life cycle cost. For the rare times most grid connections go down, a generator is a much cheaper alternative in most cases.

The following link is a interesting Tech discussion on this very subject: Simple grid-tie system, will this work? - Page 3 - Solar Electric Discussion Forum

Icarus

 

Interesting... ! We got plenty of snow this last winter and spring. I have over an acre of snow in the back yard. Don't suppose I could mold it into a parabolic reflector ?

Hydro Quebec WILL buy power back from me I think at the same rate I pay them. But it's reasonably cheap already, like just over 8 cents (taxes included) once you go over the cheap threshold, which we always do.

But with this payback deal, I won't need many batteries I guess (except for power outages) because Hydro Quebec acts like the biggest battery anyone could need.

 

Fact is you don't need any batteries at all, in fact battery back up in a solar system add greatly to the cost. In this thread that's what the Prius is for.

As for putting panels on you house. As we say in the Solar biz Solar Panels are "Sexy" Everyone wants them but, . PV solar is almost (not quite but almost) the last thing to install if your desire is to reduce you bill, or if our trying to be "green" The first is conservation, the second is conservation, and the third is conservation. Your cheapest energy dollar, by far, is the KWH you don't have to generate. A dollar spent upgrading appliances, insulation etc. go way further than a dollar spent on PV solar. The next most cost effective thing is solar hot water, passive and active solar space heat, and then,,,only then PV solar. (Followed by small scale wind. Small scale wind is a loser for most folks because of it's inherent mechanical nature, and peoples over estimation of how windy it REALLY is.

A typical grid tie PV system will cost somewhere in the neighborhood of $10/watt. It doesn't take a genius to figure out that a lot of stuff comes cheaper when you only pay $.08 kwh. PV Solar runs ~$.20kwh net.

Having said that, I am a great proponent of PV solar. If as a society we were to pay the true cost of our other energy choices solar becomes much more cost effective. What is the true cost of the environmental/social damage that Hydro Quebec caused by the James Bay projects? I bet it is way more than $.08! The fact that Hydro Quebec can sell into the US market at a much higher peak price subsidizes your $.08.

As I have said, it is time we pay the real and true cost of our energy.

Icarus

 

Icarus, great handle you have there considering what you've just said.

One of our local politicians brought up in a local French TV show last winter, the concept of Nega-Watts, which is really a good idea.

Hydro-Québec has been acting up on this, in manufacturers and with the general population with a Fridge/Freezer Replacement Program.

Hydro-Québec even pays to have French/English TV and Radio ads promoting this.
- Manufacturers only pay parts cost, HQ has the manpower to upgrade large manufacturing plants into are more energy efficient plant. Heating and lighting.
- Fridge/Freezer has to be fully functional, HQ gives out 80$ and sends someone to pick up a 10+ year old Fridge/Freezer, so that they are upgraded to a more recent model.

So by saving already used mega-watts, this unused (negative watts), can then be resold to the US at a huge profit.

It's also expanding into the housing industry, all new homes in Québec have the highest insulation norms in the country. Heat pumps and bi-energy are actively promoted.

Still, electricity throughout Québec is extremely wasted because it is so cheap.

 

BINGO!!! Same can be said for most fuels. At least HQ is trying to reduce consumption at home. OPG in Ontario isn't so smart at least in the North!

Icarus

 

If you really want to use your Prius for a home generator this is the way to do it!

PriUPS Update 26 September 2005

Not simple, but there is no reason it can't be done. Way better than buying a radio shack msw inverter and plugging it into the cig lighter!

Icarus

 

Now this is why I love this site!

I can get it so I don't have to drag out the 5500 wat gen and set it up by the poll in a blizzard. Simply back the car out of the garage and hook up!

I love it!

 

bsd43 asked:

Anyone know how many hours can you run a Prius on a 10 gallon tank in pure "generate 12V" mode?

We have just had a major ice storm here in the the North East and I have been running my pellet stove off of a 300 watt dc/ac inverter. I have it hooked up to the Prius jump start connections in the engine compartment fuse panel. I ran an extension cord into the house to run the pellet stove. As for the car, I started it with my foot on the brake and it is in "ready". I have a dryer vent pipe from the exahust going under the garage door. The car runs a few minutes for several times in an hour to recharge the HV battery. I got a full bladder of gas last night and ran the pellet stove off the car from about 10pm to about 10am this morning and I only went down one or two guess gauge blocks.

I am sure it isn't the greatest thing to do to the hv or 12v battery, but frozen toes & frozen pipes are no fun either.

 

A ready Prius, just sitting there, will burn through a full tank of fuel in 5 to 10 days. The engine comes on when its coolant temp falls below 70 oC. Or, the engine comes on when the HV SOC falls to (about) 45% and brings it up to (about) 50%. The discharge is from the (about) 200 electrical watts draw for housekeeping.

Whichever of those happens first will cycle the engine. Now, if your external load is not much and the air temperature is low, the external load might not reduce the Prius run time at all. If you max out the load on the 12 v system, you would certainly reduce run time.

 

Doug is right, temperature has an effect. My testing with a 1 kW load shows in 40 F weather a fuel burn of 0.25 gallons/hr. Without the load, in the same temperature, the fuel burn was 0.06 gallons/hr. Keeping the car out of a cold wind will improve performance. I would expect about 40-44 hours at 1 kW.

Bob Wilson

 

To maximise economy use the same rules as with driving the car. Turn the climate control to Max cold then turn it off to keep the heater from working, ensure everything is off, and try a blanket or 2 over the bonnet to keep the heat under the bonnet but it may not be good to cover all of the grill while not moving. If some of the grill is open the fans will come on if needed. Tuck the blankets under the wipers to stop the blankets falling off.

 

If using 1kW from the 12V system, would the ICE continuously run at 0.25gal/h , or would it run intermittently?

My guess would be that the ICE recharges the HV battery at a higher rate than 1kW, therefore, the ICE would intermittently run... not constantly. For example recharging the HV from 40% to 80% 10mins, then the HV has enough stored kWh to run the 12V system for a while before needing the ICE to turn on again.
Of course the coolant temp could also trigger the ICE.