PG&E Minimum Bill Charges for Gas or Gas + Electricity Together?

[STS-134]

I get that PG&E has minimum bill charges (something like $10/month) and if you don't use at least $10/month worth of electricity, you will get billed about $10 anyway. But what happens for gas service? Are the minimum bill charges for gas and electricity together, or is there a separate minimum bill for gas?

Scenario: HVAC system is on its last leg. Thinking of going with a heat pump. Currently use a gas furnace and gas water heater. Options for new HVAC system are to get an air handler with electric backup heat, or a dual fuel system with a gas furnace as the emergency heat. Gas would be cheaper BUT, if I were to get rid of the gas water heater and go with a heat pump water heater, and not use any gas at all on most months, would I be stuck paying a minimum bill for the gas part, just to have the gas available for backup heat (which probably won't be used very much in the SF Bay Area)? If a separate minimum applies for gas service, it might be better to go with the air handler and electric backup heat, while if not, I wouldn't see an issue with getting a gas furnace as the backup, since it's actually a little cheaper than the air handler with electric backup heat, even if the gas doesn't get used very much at all.

 

[jboy210]

On my bill, gas and electricity are two separate charges with their own fees, tiers, allowances, surcharges, etc. However, I do not see a separate minimum for gas. I suspect it is part of the tier allowances.

 

[STS-134]

On my bill, gas and electricity are two separate charges with their own fees, tiers, allowances, surcharges, etc. However, I do not see a separate minimum for gas.

Doesn't the minimum only show up if you use less than the minimum bill charge? In other words, I do not see the minimums for electricity because I always use more electricity every month than the minimum charges. And it's the same for gas, because I currently use a gas water heater and even the summer usage exceeds $10/month.

I suspect it is part of the tier allowances.

What do you mean by that?

 

[Redhill_qik]

I get that PG&E has minimum bill charges (something like $10/month) and if you don't use at least $10/month worth of electricity, you will get billed about $10 anyway. But what happens for gas service? Are the minimum bill charges for gas and electricity together, or is there a separate minimum bill for gas?

Scenario: HVAC system is on its last leg. Thinking of going with a heat pump. Currently use a gas furnace and gas water heater. Options for new HVAC system are to get an air handler with electric backup heat, or a dual fuel system with a gas furnace as the emergency heat. Gas would be cheaper BUT, if I were to get rid of the gas water heater and go with a heat pump water heater, and not use any gas at all on most months, would I be stuck paying a minimum bill for the gas part, just to have the gas available for backup heat (which probably won't be used very much in the SF Bay Area)? If a separate minimum applies for gas service, it might be better to go with the air handler and electric backup heat, while if not, I wouldn't see an issue with getting a gas furnace as the backup, since it's actually a little cheaper than the air handler with electric backup heat, even if the gas doesn't get used very much at all.

Both electricity and gas have their own minimum charges and these are documented in each tariff rate schedules Tariffs. The minimums are the same across all of the residential electric tariffs (E-1, E-TOU-C, EV2A, etc). Currently the electric delivery charge is $0.34810/day and the gas minimum transportation charge is $0.13151/day or $4.07/month (31 days).

For the gas side, you have to use only 1-3 therms per month before the minimum kicks in, if you are using more therms then the $1.36083/therm transportation charge exceeds the monthly transportation charge. When I switched my gas water heater to an electric hybrid water heater I started seeing this in the gas section on my PG&E blue bill as an "Additional transportation charge" line item. Last month with only 2 therms this was an extra $1.43, the prior month with 3 therms it was only $0.09. The gas transportation rate has since increased, so it should be $0.00 with 3 therms now.

 

[STS-134]

Both electricity and gas have their own minimum charges and these are documented in each tariff rate schedules Tariffs. The minimums are the same across all of the residential electric tariffs (E-1, E-TOU-C, EV2A, etc). Currently the electric delivery charge is $0.34810/day and the gas minimum transportation charge is $0.13151/day or $4.07/month (31 days).

For the gas side, you have to use only 1-3 therms per month before the minimum kicks in, if you are using more therms then the $1.36083/therm transportation charge exceeds the monthly transportation charge. When I switched my gas water heater to an electric hybrid water heater I started seeing this in the gas section on my PG&E blue bill as an "Additional transportation charge" line item. Last month with only 2 therms this was an extra $1.43, the prior month with 3 therms it was only $0.09. The gas transportation rate has since increased, so it should be $0.00 with 3 therms now.

Okay, that sucks. Do you know whether homes in areas where PG&E provides gas service are required to actually have gas service, or would one be able to avoid the minimum charges by shutting off the gas service to the home? I know that going off grid (for electricity) isn't permitted, and if the minimums are unavoidable, getting a gas furnace as a backup heater seems like a reasonable option. Otherwise, it risks incurring minimum charges all summer long and probably for several months in the fall and spring as well.

 

[Redhill_qik]

Okay, that sucks. Do you know whether homes in areas where PG&E provides gas service are required to actually have gas service, or would one be able to avoid the minimum charges by shutting off the gas service to the home? I know that going off grid (for electricity) isn't permitted, and if the minimums are unavoidable, getting a gas furnace as a backup heater seems like a reasonable option. Otherwise, it risks incurring minimum charges all summer long and probably for several months in the fall and spring as well.

I don't know, but with multiple cities no longer allowing new construction to have gas pipeline connections you should be able to fully terminate gas service. Best option would be talk with PG&E Customer Service.

Worst case, they might want you to remove the meter and cap the line to avoid charges. Something along these lines for construction projects that require it

https://www.pge.com/includes/docs/pdfs/shared/customerservice/otherrequests/newcontruction/BRSC_Guide_GasServiceRemoval.pdf

 

[tfan2018]

Gas has its own minimum delivery charge. I found out when I disconnected all my gas appliances but didn’t cancel gas service yet. I was still billed ~$4.50 per month

 

[STS-134]

I don't know, but with multiple cities no longer allowing new construction to have gas pipeline connections you should be able to fully terminate gas service. Best option would be talk with PG&E Customer Service.

Worst case, they might want you to remove the meter and cap the line to avoid charges. Something along these lines for construction projects that require it

https://www.pge.com/includes/docs/pdfs/shared/customerservice/otherrequests/newcontruction/BRSC_Guide_GasServiceRemoval.pdf

So I called PG&E and they said yes, the minimum bill charge is 13.151¢/day. You can avoid the minimum bill charges by having them "lock out" the meter, thus terminating your gas service.

Now the interesting part: I found the detailed specifications for the heat pump. They give the kW consumption and the output of the heat pump in BTU/hr at various outdoor (evaporator coil) temperatures. From this we can calculate the COP values:

2.12 @ 17°F/-8.3°C
2.60 @ 27°F/-2.8°C
3.09 @ 37°F/2.8°C
4.08 @ 47°F/8.3°C
4.52 @ 57°F/13.9°C

If you're able to stay in Tier 1 for gas, you're being charged $1.98/therm. With an 80% AFUE gas furnace as your backup heat source, you are being charged $1.98 for 105,506,000 J of heat, 80% (or 84,404,800 J) of which makes it into the house. This is about 42,628,687 J of heat per dollar spent.

There are 3,600,000 J in one kWh. We can therefore calculate the COP at which gas and electricity are equal, but first, you need to know the cost of one kWh of electricity. Now, PG&E's electric rates are an absolute ripoff, and on the E-TOU-D rate plan, they're charging approximately 35¢/kWh (actually it's around 38¢/kWh peak and 34¢/kWh off-peak during winter, but I just rounded to 35¢/kWh for simplicity). $1 worth of electricity, at this rate, gives us 1/.35=2.857142857 kWh which is 10,285,714 J of energy. This means that to get exactly 42,628,687 J per dollar, we need a COP of 42,628,687/10,285,714 = 4.14. So the crossover point, at $2/therm at 35¢/kWh, is just over 47°F/8.3°C. This certainly covers most winter days during daytime hours, and especially afternoons and evenings, around here. The key is keeping yourself in tier 1 though, because if you go into tier 2 for gas usage, you're paying about $2.45/therm which means that $1 only gets you 34,450,939 J of heat. In this case, the COP at which electricity becomes more expensive than gas moves down to 34,450,939/10,285,714 = 3.35, which is somewhere around 39-40°F/3.8-4.4°C. So if you get a dual fuel system, and you're on E-TOU-D, you should probably set the transition temperature to somewhere around 45°F/7.2°C.

One option of course is to go with electric supplemental heat, and disconnect the gas service if heat pump water heaters ever stop sucking (no guarantees on that though). But a gas furnace is actually cheaper than a fan coil with supplemental heat in it, believe it or not. And although the supplemental heat will not be kicking in on that many days in the SF Bay Area, as a percentage of the time the house needs heat, those colder night take up a much higher fraction the total than the number of hours of the year they represent. So at this point, I'm considering just going with the dual fuel system and then no matter what happens with gas rates or electric rates, or if I were to get solar in the future, or if the NEM rules change, I can just adjust the point at which the system switches over.

 

[tfan2018]

What’s wrong with heat pump water heaters? I installed my Rheem hybrid and I am loving the savings with no issues on recovery rate for the past few months

 

[STS-134]

What’s wrong with heat pump water heaters? I installed my Rheem hybrid and I am loving the savings with no issues on recovery rate for the past few months

Heat pump water heaters are way too weak. Have you looked at the specs on that Rheem hybrid? 4200 BTU/hr in heat pump mode. That's a recovery rate of around 8-10 gallons per hour. And Rheem is not at all transparent about this. They don't put the heat pump only recovery rate on the literature, only some obscure BTU/hour rating from which I had to calculate recovery rate assuming an inlet temperature of 65°F and outlet temperature of 130°F.

I don't know why Rheem insists on putting the evaporator and compressor on the same housing as the tank. I think it's weak because they don't want the room it's sitting in to freeze, but the way to deal with this issue is to put the evaporator outdoors. If you have two people take a shower back to back, it will revert to inefficient and expensive electrical resistance heating, which is the only way it can achieve its advertised first hour rating. There are some decent heat pump water heaters with good recovery rates like this one which is a commercial unit. But I have never seen a residential one with decent specifications.

 

[tfan2018]

I’ve looked at the specs and in reality my Rheem hybrid has exceeded my expectations. It’s super energy efficient and I have not had any issues with the recovery rate exclusively in heat pump mode. The kicker is that it cools and dehumidifies my garage too.

We’ve taken showers back to back and I have not seen it revert to electrical mode ever. Our garage is uninsulated so its working out very well for the heat pump. You could get the 80G tank if recovery rate is a concern. We are fine with our 50G. We generally take showers at night and heat pump mode runs for 2-4 hours. We’ve taken showers during the daytime and the temp recovers even quicker due to the garage temp. I’ll need to see how the performance is during winter.

I haven’t had an instance where I wish I had my Rheem gas heater back instead. We came from a 40G gas heater and we actually ran out of hot water for showers sometimes.

Of course having solar panels powering everything and ditching the gas bill feels amazing.

 

[BGbreeder]

What’s wrong with heat pump water heaters? I installed my Rheem hybrid and I am loving the savings with no issues on recovery rate for the past few months

Noise.

Here the installation location would be within 10' of sleeping spaces without extensive replumbing. At 72db, that is way too close. A remote garage location would be great.

 

[wwu123]

Heat pump water heaters are way too weak. Have you looked at the specs on that Rheem hybrid? 4200 BTU/hr in heat pump mode. That's a recovery rate of around 8-10 gallons per hour. And Rheem is not at all transparent about this. They don't put the heat pump only recovery rate on the literature, only some obscure BTU/hour rating from which I had to calculate recovery rate assuming an inlet temperature of 65°F and outlet temperature of 130°F.

I don't know why Rheem insists on putting the evaporator and compressor on the same housing as the tank. I think it's weak because they don't want the room it's sitting in to freeze, but the way to deal with this issue is to put the evaporator outdoors. If you have two people take a shower back to back, it will revert to inefficient and expensive electrical resistance heating, which is the only way it can achieve its advertised first hour rating. There are some decent heat pump water heaters with good recovery rates like this one which is a commercial unit. But I have never seen a residential one with decent specifications.

I think the point is a "hot" shower is a mix of hot water from the water heater tank and cold water to somewhere around 100-110°F, so one 10-min shower might use about 10 gallons depending on cold water temp. And the point of having a larger tank is there's enough buffer for several back-to-back showers, although the tank temp slowly drops as it refills with cold supply water. You can also set the tank temp to higher than 130°F to make a given tank buffer last longer, as opposed to getting a bigger tank, though either option you increase your standby energy losses.

I think they spec the recovery rate that way, because your inlet temperature varies throughout the year as well as varies for different regions; and you can choose different tank temperatures. But they could make it easier to interpret, convert BTU/hr to gal-°F/hr (divide by 8.33)....

 

[sunwarriors]

We are considering those Rheem hybrid water heaters once ours die as well. So is the thought for people who switched from pure gas water heaters to these newer types to get the largest one possible?

Our garage is too hot so that's a blessing if it can cool it down as well, but concerned with back to back showers as some folks mention above. If having a bigger tank or biggest you can live if will be safer, please share thoughts/suggestions and we'll probably head that route.

With that and the future variable speed A/C, hoping those newer techs will cut down our energy usage when there is no sun.

 

[STS-134]

I’ve looked at the specs and in reality my Rheem hybrid has exceeded my expectations. It’s super energy efficient and I have not had any issues with the recovery rate exclusively in heat pump mode. The kicker is that it cools and dehumidifies my garage too.

We’ve taken showers back to back and I have not seen it revert to electrical mode ever. Our garage is uninsulated so its working out very well for the heat pump. You could get the 80G tank if recovery rate is a concern. We are fine with our 50G. We generally take showers at night and heat pump mode runs for 2-4 hours. We’ve taken showers during the daytime and the temp recovers even quicker due to the garage temp. I’ll need to see how the performance is during winter.

I haven’t had an instance where I wish I had my Rheem gas heater back instead. We came from a 40G gas heater and we actually ran out of hot water for showers sometimes.

Of course having solar panels powering everything and ditching the gas bill feels amazing.

Where do you live and how long have you had the Rheem hybrid? Like any heat pump, its COP and how much heat it can deliver dramatically depends on the difference in temperature (another reason I'm not a fan of ratings that show a single BTU/hr or COP value or whatever the units are any more than single mpg or Wh/mi values that assume you're always driving in specific conditions at a specific speed). The 4200 BTU/hr rating was likely measured under the standard test conditions:

2. Test Conditions.

2.1 Installation Requirements. Tests shall be performed with the water heater and instrumentation installed in accordance with section 4 of this appendix.

2.2 Ambient Air Temperature. The ambient air temperature shall be maintained between 65.0 °F and 70.0 °F (18.3 °C and 21.1 °C) on a continuous basis. For heat pump water heaters, the dry bulb temperature shall be maintained at 67.5 °F ±1 °F (19.7 °C ±0.6 °C) and the relative humidity shall be maintained at 50% ±2% throughout the test.

2.3 Supply Water Temperature. The temperature of the water being supplied to the water heater shall be maintained at 58 °F ±2 °F (14.4 °C ±1.1 °C) throughout the test.

2.4 Outlet Water Temperature. The temperature controllers of a storage-type water heater shall be set so that water is delivered at a temperature of 125 °F ±5 °F (51.7 °C ±2.8 °C).

2.5 Set Point Temperature. The temperature controller of instantaneous water heaters shall be set to deliver water at a temperature of 125 °F ±5 °F (51.7 °C ±2.8 °C).

In other words, dry bulb of 67.5°F, ambient temperature of 65-70°F inlet temperature of 58°F, outlet temperature of 125°F. Of course, as the water in the water heater cools, the heating capacity goes up, and so does recovery rate. But if your garage is 90-100°F on a hot summer afternoon, it's likely doing at least double its rated heating value, possibly more. At this point, I could easily see it handling 2 back to back showers. The real question is whether it will be able to keep up when the garage temperature falls to 40°F in the winter time (unless you're in a place like Hawaii, in which case you don't have to worry about this). I would expect the recovery rate to be significantly worse than the rated output suggests at that point. Like, maybe just half of its rated value, and only 1/4 of what it was with a 90-100°F evaporator temperature. And whether it can handle back to back showers, running the dishwasher/washing dishes, and doing laundry all within 1 hour, without reverting to electric resistance heating, I'm not sure.

By the way, if you're saying that it "cools and dehumidifies my garage too" and you mean that there's a noticeable decrease in temperature in there on a hot summer day, that's going to really work against you in the winter time. It's conceivable that the garage temperature could even get much colder than the outdoor air on a cold night. I think the real solution to this, long term, is to tie the water heater into the HVAC heat pump system (an evaporator/condenser outdoors, an evaporator/condenser indoors, and a condenser in the water tank), with refrigerant valves that manage everything. Sort of like what Tesla did with the octovalve. There are times when you want to cool the house and heat the water simultaneously and it's kind of dumb to run two separate systems to do this, dumping waste heat into the atmosphere while at the same time taking heat from the atmosphere and pumping it into the water.

Noise.

Here the installation location would be within 10' of sleeping spaces without extensive replumbing. At 72db, that is way too close. A remote garage location would be great.

Yeah, that's an issue too. There's a good reason why the compressors for central heat pumps/air conditioners are installed outside the building envelope. I really don't get why they don't residential have hybrid water heaters with the evaporator and compressor outside the building envelope. Would really cut down on the noise level. My water heater is in the garage, so noise isn't a huge issue, but I would still be able to hear it from the kitchen and family room. Put a much more powerful compressor outside the building envelope though, and it becomes a lot quieter from inside and far less likely to revert to backup heat.

 

[BGbreeder]

@STS-134 I agree that putting a compressor upside can help. OTOH, the prior generation of Rheems were 20-25db quieter, which is a huge improvement on the current generation of HPHWs. I wonder about efficiency loss if you aren't running your AC often, there are no small amount of efficiency losses that happen in running a large HVAC for a small water heater.

 

[STS-134]

@STS-134 I agree that putting a compressor upside can help. OTOH, the prior generation of Rheems were 20-25db quieter, which is a huge improvement on the current generation of HPHWs.

Wait...they made the heaters noisier? Why would they do that?

I wonder about efficiency loss if you aren't running your AC often, there are no small amount of efficiency losses that happen in running a large HVAC for a small water heater.

I would actually think that the losses wouldn't be that much greater than they are when the HVAC system comes on to cool or heat the house. Yes, the house is a much larger volume than a water heater on one hand, but on the other, it's heating or cooling air, which has a much lower specific heat capacity and density than water. I think the key here, if this really is an issue, is allowing a large enough temperature swing in the water tank that the system isn't always switching on and off.

 

[wwu123]

By the way, if you're saying that it "cools and dehumidifies my garage too" and you mean that there's a noticeable decrease in temperature in there on a hot summer day, that's going to really work against you in the winter time. It's conceivable that the garage temperature could even get much colder than the outdoor air on a cold night. I think the real solution to this, long term, is to tie the water heater into the HVAC heat pump system (an evaporator/condenser outdoors, an evaporator/condenser indoors, and a condenser in the water tank), with refrigerant valves that manage everything. Sort of like what Tesla did with the octovalve. There are times when you want to cool the house and heat the water simultaneously and it's kind of dumb to run two separate systems to do this, dumping waste heat into the atmosphere while at the same time taking heat from the atmosphere and pumping it into the water.

Yeah, that's an issue too. There's a good reason why the compressors for central heat pumps/air conditioners are installed outside the building envelope. I really don't get why they don't residential have hybrid water heaters with the evaporator and compressor outside the building envelope. Would really cut down on the noise level. My water heater is in the garage, so noise isn't a huge issue, but I would still be able to hear it from the kitchen and family room. Put a much more powerful compressor outside the building envelope though, and it becomes a lot quieter from inside and far less likely to revert to backup heat.

Very simple, what we need is them to invent a combo all-in-one heat pump water heater and chest freezer unit for the garage - keeps the water hot and the meats/ice cream cold, while the garage just stays whatever temperature it is....

 

[BGbreeder]

Wait...they made the heaters noisier? Why would they do that?

I would actually think that the losses wouldn't be that much greater than they are when the HVAC system comes on to cool or heat the house. Yes, the house is a much larger volume than a water heater on one hand, but on the other, it's heating or cooling air, which has a much lower specific heat capacity and density than water. I think the key here, if this really is an issue, is allowing a large enough temperature swing in the water tank that the system isn't always switching on and off.

Yes, they did. And not by a little, either.

You would have to ask Rheem and get them to go on the record. There is lots of speculation on the internet, much of it to the effect that the extra noise is a result of a design to reduce manufacturing cost, but I haven't seen an answer from Rheem. As they haven't fixed the issue, I draw the conclusion that the new design is intrinsically noisy, and it either would cost too much to manufacture an improved design, or in running costs for them to redesign it. Either way, they seem to be sticking to this design, so if you want a quiet HPHW, you probably need to be looking at other brands.

With a variable speed compressor, throttling up or down is easy, but my limited experience with compressor systems is that they work well over a range, e.g. 20-100% output, and the efficiency is not uniform across that, usually improving towards 100%, for reasons of parasitic losses (friction, heat flows, etc.) Most home hot water use is episodic, and not large, excepting perhaps teenage showers. I think using an AC unit to preheat 80 gallons would make sense, but only if you are a regular user of AC. I'm just not convinced it is terribly efficient for the primary heat source. I would love to be proved wrong. Solar water preheat can work in many locations, but it is a pain to plumb, and often not terribly great ROI.

All the best,

BG

 

[BGbreeder]

Very simple, what we need is them to invent a combo all-in-one heat pump water heater and chest freezer unit for the garage - keeps the water hot and the meats/ice cream cold, while the garage just stays whatever temperature it is....

Sign me up!