Indirect Water Heater to Electric

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Jaytatis23

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Okay guys so I bought a house in Jan. My indirect started leaking so I’m looking to replace with an Electric Water Heater due to wanting to keep the boiler off during summer months

I know I can just buy another indirect and just basically plug and play with the existing connections.

can anyone give me a quick run down on how to make this switch or is it even possible.

Thank you.

I have this boiler.
https://www.homedepot.com/p/Slant-F...000-BTU-Output-without-Coil-LD-30-P/312732854

and just bought this electric water heater
https://www.homedepot.com/p/Rheem-P...ric-Tank-Water-Heater-XE40M06ST45U1/205810725
 

Fitter30

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Indirect where is it exactly? At boiler or tank? Take a pic. Electric would just have to pipe the cold and hot water lines to the correct lines. Can get rid of the indirect tank.
 

Jaytatis23

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Indirect where is it exactly? At boiler or tank? Take a pic. Electric would just have to pipe the cold and hot water lines to the correct lines. Can get rid of the indirect tank.
73-D7-B4-A8-B74-B-449-C-B190-FD244-A045872.png


This is my current set up.
 

Jadnashua

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Swapping to an electric WH isn't a big deal, but depending on what your fuel use is, and the type of boiler, it may not save you much. Keep in mind, that an indirect typically has a MUCH faster recovery rate versus the typical electric one, so you might need a larger tank. Many more modern boilers are designed to cold start, so that means in the summer, they only turn on when the WH calls for heat...IOW, they're not running in standby, already hot.

Do you have a spare 30-40A in your panel? You might consider a heatpump WH, it's more efficient than a pure resistance one.
 

Dana

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You might consider a heatpump WH, it's more efficient than a pure resistance one.

The heat pump water heater (HPWH) idea would be a great if he hadn't already bought the plain old electric tank... :( Consider it an opportunity loss.

Or maybe not.

If it hasn't already been unpacked it may be returnable for a restocking fee, or even for store credit against an HPWH.

The summertime outdoor dew points in Carmel NY are high enough that basements generally need mechanical dehumidification to keep the musty basement stink at bay, and a heat pump water heaters take on some of that dehumidification load, converting & storing the latent heat of vaporization of the moisture in the air into heat inside the insulated tank.

During the heating season the HPWH harvests the standby & distribution losses of that (surely oversized) boiler, storing it in the tank. Lowering the temperature of the boiler room a degree or two in winter lowers the overall heat loss out of the house, for higher net efficiency.

Any time of year any standby losses of the HPWH get restored back into the tank at 1/4-1/3 the cost of replacing that standby loss heat into the water with a resistance element.

With a plain old electric tank you get none of that. The operating cost of a current model HPWH is typically under 1/3 that of an electric tank, and a cheaper way to heat the domestic hot water than almost any other method (including condensing natural gas.)
 

Reach4

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On my latest gas bill, there are 4 items that are a $number * the number of therms used. The sum of those 4 $numbers is $0.65. I understand that will go up in the winter.


Then there are taxes based on a total prices (which are partially due to therms), and Qualified Infrastructure Chrg, which may be based on my peak month. Not sure how that goes.

And there is a fixed charge. But for comparison, I only want the marginal cost. So with tax, maybe call that $0.70 or so currently.

https://www.efficiencymaine.com/at-home/water-heating-cost-comparison/? is a nice comparison site.

But then my marginal electricity cost per kWh is lower than the default of that site too.
 

Dana

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On my latest gas bill, there are 4 items that are a $number * the number of therms used. The sum of those 4 $numbers is $0.65. I understand that will go up in the winter.

FWIW: That's less than half what people in MA are paying for gas, even last year, when Henry Hub spot prices were at record lows. This year the wholesale prices of gas have gone up substantially, especially for gas-grids fed by LNG (such as New England's capacity-constrained pipelines) due to increased international demand for LNG.

QUOTE="Reach4, post: 695678, member: 61511"]
But then my marginal electricity cost per kWh is lower than the default of that site too.[/QUOTE]

Most of southern New England's residential retail electricity prices are well north of 20 cents, some (like mine) north of 25 cents. With a much smaller population with plenty of low to zero marginal cost hydro & wind resources to work with Maine is something of a regional outlier.

The coming build out of large scale offshore wind is likely to put a dent in retail prices in southern New England too, but the delivery (essentially grid maintenance and meter reading) costs here are still much higher than the national average for a variety of reasons. Where net-metered (=true for more than half of MA) rooftop solar PV is now nearly half the cost of the current grid sources on a lifecycle basis, and that's before any tax credits SRECs or other subsidies get factored in.

In my neighborhood where the delivered retail cost of electricity is a~25 cents and gas is north ~$1.70/therm at a UEF of 3.5 (HPWH) and 0.90 (condensing tankless) every kwh delivers ~12,000, BTU, which is (1,000,000/12,000=) 83 kwh/MMBTU, or (x $0.25=) $23/MMBTU. Each therm of gas delivers 90,000 BTU,or (1,000,000/90,000=)11 therms/MMBTU, or (x $1.7/therm=) $19 /MMBTU. That may seem like a big difference in operating cost until the higher maintenance and installation costs get factored in, making it essentially a wash at best.

Looking forward on energy policy and future energy pricing there's little room for local NG prices to go down (remember, wholesale prices hit all time lows last year), yet the even lifecycle cost of rootop PV (15 cents or less for most of New England, using reasonable discount rates in the present-value analysis) leveraged with an HPWH is already much cheaper hot water than current and probably future condensing gas.

Similarly, for space heating the cold climate heat pumps are pretty much at operating cost parity with mid 80s AFUE efficiency gas boilers & furnaces at the gas & power grid prices, but cheaper than condensing gas heating appliances if one has net metered PV.

Predicting energy price futures is a bit of a risk, but the market and policy pressures seem to be shifting in favor of heat pumps vs. gas both in New England and elsewhere. We will know the price impact of offshore wind well before 2030, since the zero marginal cost wind power will be primarily displacing combined cycle natural gas and single cycle gas peakers, currently responsible for about half the power going on to the ISO-New England grid. The more wind that gets built, the lower the operating capacity factors (and the higher the cost) of the gas fired power.

So far no states in the region are offering subsidies for switching from gas to electric water & space heating (there is subsidy available for many in the region to switch from higher priced oil or propane to heat pump water & space heating), but given the stated policy goals by the MA govern0r Baker (R) administration some carrots (or sticks) will need to be applied soon. The Baker administration recently appointed a Clean Heat Task Force to come up with a plan on how to get there.
 

Reach4

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I did not look back at winter rates, but I expect they are significantly higher. The utility here buys a lot of gas in the summer, and stores it in old gas wells.

The coming build out of large scale offshore wind is likely to put a dent in retail prices in southern New England too,
I think that supposes subsidizing the wind farms by somebody other than the rate payers, I think. I could be mistaken, of course. Here they subsidize wind farms to the tune of about 6 cents/kWh if I remember correctly. So occasionally the realtime rates go negative, I presume because with the subsidy that can overcome a small negative. Of course delivery charges get added, so it never comes out net negative for the end user.
 

Dana

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I think that supposes subsidizing the wind farms by somebody other than the rate payers, I think. I could be mistaken, of course.

Up through 2025 there is still a 30% Federal investment tax credit for offshore wind, which may or may not be going away thereafter. I don't believe any of the current offshore wind developers in MA have opted for production credits as the alternative.

The legislatively mandated offshore wind procurements in MA specify a minimum total capacity, and there will be a guaranteed minimum price/MWh up to contract production levels, all determined by an open bidding process. More discussion of the bid & price structures can be found here. There will be more, since that was just the first of three tranches. There is no subsidy- it's all built onto contract price, and the large utility buyers of those contracts are allowed to pass on those costs to the ratepayers. But every time new bids are opened up, they come in substantially cheaper than projected when the MA offshore wind mandates went into effect. The party is still getting started, but there really isn't any stopping it at this point.

What doesn't show up in the contract price is the effect on spot-market localized marginal price (LMP) and day-ahead electricity price markets. As a zero marginal cost supplier the wind operator can put in $0 bids into spot markets and move to the head of the dispatch queue, accepting whatever price gets set by the next-most-expensive supplier. During times of high demand extreme spot market pricing is common, but when there are $0 bidders of any significant capacity those numbers are VERY well damped, making it harder for low capacity factor #2 jet peakers or single cycle gas peakers to break even, since their capacity factors get smaller whenever there is $0 marginal cost goods active on the grid (whether solar or wind.)

In New England the highest wholesale electricity prices usually happen during air conditioning peaks, but there are also times when a Polar Vortex disturbance cold snap puts enough space heating load on the regional gas grid that supplies to combined cycle gas plants have to be curtailed, sending electricity market prices into the stratosphere for days, and all the oil fired plants are running flat-out getting fat. The heavy cost to utilities of the extreme winter peaks are a serious driver of retail rates, which in MA get adjusted twice per year. A meteorlogically statistical fact of New England life is that average offshore wind speeds pick up substantially cold snaps, particularly during the first half of cold snaps, which will inevitably cut those extreme price peaks off at the knees due to the excess zero margin capacity. This would be the New England version of how even combined cycle gas plants in Texas can become uneconomic in the presence of large scale wind development (despite the radically different market structures in ISO-NE vs. the freewheeling ERCOT.)

Another factor entering the local electricity markets now and on to 2030 are the electricity storage mandates, which will be able to under-price most grid services such as voltage & frequency stabilization by a substantial amount, services previously served by peakers. That party too is just getting started.

Of course the pipeline developers were all for installing higher capacity gas infrastructure to get around the weather induced price-peakiness, and were lobbying hard to push their costs (and risks) onto the electricity ratepayers. A substantial amount of analysis contracted for by the MA Attorney General's offices showed that in the early years that was likely to lower retail electricity prices slightly, but would inevitably lead to much higher prices later sticking the electric ratepayers with a stranded asset (due to already legislated carbon emissions limits) well before the pipeline was paid off. It's widely speculated that the real driver for the enhanced pipeline were those looking to develop an LNG export capacity in Maine or Nova Scotia, which would have increased the price of gas to New England ratepayers (both gas & electric). Saddling the electric ratepayers for the risk and delivering the LNG export profits to the pipeline developers & gas producers is a great deal for the investors- can't blame them for trying. But the Attorney General's report pretty much took a sledge hammer to their dreams.

The cost of wind & solar & battery storage are continuing to decline on fairly aggressive learning curves. Economist Tony Seba's new think tank "ReThink-X" ran the weather data and conservatively projected numbers for the ISO-NE , CAISO, and ERCOT regions and determined that even without building out more grid infrastructure OVERBUILDING solar + wind + battery storage would be sufficient to provide reliable 24/365 power to each of those grids, and that the sweet-spot mixes for each region using just those three technologies would be even cheaper than keeping the existing power generators running. Whether/when that happens or not is a choice only somewhat steerable by policy makers. The raw economics of it are compelling- one way or the other dirt-cheap electricity is coming in most of our lifetimes, with or without tax credits or other subsidies. Just as the large telephone companies passed on running the internet back in 1980 (who would ever use that stuff?) and dismissed cellular telephones as too tiny to be bother with in 1990, most of the utilities and oil/gas industry insiders right now have barely an inkling just how badly they will be clobbered by the tsunami of ubiquitous & cheap renewables & storage by 2030.

In a similar and related disruption, US auto makers (other than Tesla) have been caught short, and have very little hopes of competing with the Chinese electric vehicle vendors. The recently released X-Peng P5 is something of a Toyota-Camry sized luxury car priced under $25KUSD (without subsidy). BYD's EA-1 (aka "Dolphin") released this year is roughly like Honda Fit or Toyota Corolla in size & appointments, starting at under $15KUSD for the smaller battery model (which is still good for north of 170 miles on single charge the bigger battery versions can go more than 400 miles)). BYD is a vertically integrated company- they make their own batteries (and are the 4th largest battery maker in the world), and even their own chips. Their lithium iron phosphate batteries are the safest on the market (it's hard to set them on fire), and their battery cost is substantially lower than Tesla's.

Speaking of Tesla- their Shanghai factory is delivering more cars than their flagship factory in Fremont CA, and they are current in the process of doubling it's size, expecting to be on line before the end of 2022. Up until recently many/most of the Shanghai Teslas were being exported, but that has changed over the past quarter, and in September fewer than 5000 of the ~56000 cars produced stayed in China(!). At the same time, the Tesla Model 3 outsold all German internal combustion cars of similar size & luxury in Germany last month! The European car makers are mostly in the same boat as the US (maybe half a paddle-stroke ahead), but the head of VW commented the other day that it takes Tesla 8 hours to make a Model 3 compared to 30 hours for VW's ID-3 or ID-4 EVs. And this comes even before Tesla's giga-factory Berlin is up and running, selling mostly imported (from China) Model-3s. The gross margin on the Shanghai Model 3s is something like 29-30% (way better margins than any European or US produced car of any type), and the quality is better than the Fremont CA produced Model-3s. It's really going to be hard for the European incumbents to compete in that segment of the market (but BYD & X-Peng probably can.)

GM is pretty much screwed on getting EV traction in the US after the Chevy Bolt battery fires fiasco. In China they have partnered with WuLing to make the Mini, a diminutive but sturdy ~$5000 USD (yes, the decimal point is in the right place) electric car currently a hot seller in China, coming to Europe in 2022 (?), but that's a far cry from the money they are accustomed to making on pickups and SUVS. Unless they can come up with a pickup EV more compelling than Ford's F150 EV, (let alone a Rivian or Tesla Cybertruck) before 2024 they may go bust by 2030. The demand is there- the Cadillac Lyriq electric SUV pre-orders sold out in under a half hour, but deliveries are still many months out, with no promises or ability to meet the (apparent) high demand. (Can they even get enough batteries delivered in time to meet their paltry Lyriq production schedule?) Ford isn't in particularly better shape. They say they are going to build a large EV & battery plant in TN, but they are even right now carrying a lot of debt on BB grade bonds (one step above junk bond status), and it's not clear where they'll be getting enough capital to pull that off.

OK, that's enough mega-slackin' for me today- time to go serve the paying customers.:)
 

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The heavy cost to utilities of the extreme winter peaks are a serious driver of retail rates, which in MA get adjusted twice per year.
No option for realtime rate for homes? That is what I do, which means turning stuff off at occasional high rates. Tho there is theoretically no connection to TX, when they had their bad weather, my rates went up a lot.

Are the wind farms going to be able to operate during a nor'easter, or will they need to shut them down in the face of high winds or icing?
 

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No option for realtime rate for homes? That is what I do, which means turning stuff off at occasional high rates.

Varies by utility company. Most of the larger utilities in MA do not offer time of use rate structures available for residential ratepayers. Utilities in MA are financially energy-decoupled, and aren't allowed to own more than some percentage of the generation assets. The generators are independent operations, and the utilities are required to make 6 month contracts with generators sufficient to fill their anticipated demand. Ratepayers are allowed to contract with energy suppliers/brokers independent of the utility for their own energy portion of the bill rather than accept the utilities standard mix. (I'm currently in the middle of a 2- year contract for 100% wind power through a broker, and it's cheaper than the mix offered by the utility.)

In some parts of MA there are small municipal power companies operating as the local monopoly, and they can enter into very long term contracts with generators, and are usually quite a bit cheaper than the three largest utilities that own the lion's share of the market.

In short, it's complicated, but I personally cannot sign up for TOU or dynamic spot market rates.

Tho there is theoretically no connection to TX, when they had their bad weather, my rates went up a lot.

When TX had their crippling polar vortex disturbance cold snap so did most of the upper midwest. The reason it was less crippling for the grid in the upper midwest is because TX gas distribution pipelines do not dry the gas, and the equipment ices up whereas the regulatory environment in your area requires equipment & materials tolerance of sub-zero temperatures across the board. Similarly, wind farms in the upper midwest are designed to operate in sub-zero temps (TX not so much though most fared OK during that event), and cooling systems on nukes in the upper midwest are designed to not ice up. (I believe only one nuke in TX had to go offline during the event, but one nuke is a pretty big hit.) Most of the midwest did not see power outages, and due to the higher connectivity (as compared to ERCOT) to adjacent grids power can (and was) imported when generators had to go off line. (IIRC Oklahoma had some problems, but kept the lights on with imports.)

Are the wind farms going to be able to operate during a nor'easter, or will they need to shut them down in the face of high winds or icing?

The offshore wind farms are designed for much higher winds than most onshore systems. I don't have the specs at hand, but they are designed operate just fine at normal nor'easter wind speeds, but may have to shut down during a hurricane. Normal nor'easters fairly often ended up having to take one of the coastal nukes in MA offline (before it was retired) due to the fragility of it's grid interconnections, but the grid connections to the wind farm undersea cabling are designed to be more robust.
 

Reach4

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but the grid connections to the wind farm undersea cabling are designed to be more robust.
Still, a ship anchor could do them in, as it seems that California offshore pipeline succumbed to. But at least there is no spillage with electric.
 

Dana

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Still, a ship anchor could do them in, as it seems that California offshore pipeline succumbed to. But at least there is no spillage with electric.

Not likely giving the locations of the wind farm areas relative to shipping lanes, and the fact that there is redundancy built into the cabling between the wind farm array and the on shore connection point.

A mishap like that may be able to take one of the 62 turbines, but not the whole array. That number is down from 108 in the initial design, with the arrival of GE's gian-normous GE Haliade-X in time the first phase development, but there is now a 14MW version available so the number may drop to 57 by the time it's ready to go online.

You'd almost think they maybe-kinda thought about those kinds of reliability & vulnerability issues ahead of time, eh? :) (It was all in the RFP spec.)

The Haliade-X (dwarfs anything you would ever see in an onshore wind farm.

Wind_turbine_heights.jpg


ge_haliade-x_nacelle_4_0.jpg


For yuks I looked up the max operational speed (= 111 mph) and the maximum gust tolerance (= 157 mph) requirements for the offshore array. Typical nor-easters see maximum winds <75mph, but could in rare instances will approach or exceed the 111 mph operational limits for a few hours at a time, but nowhere near as long as a whole day (or even half a day).

The minimum annualized capacity factor is very conservatively estimated to exceed 45% in even the lowest wind years, with typical years in the 55% range. The winds are both higher and more reliable winter, making it something akin to 400-500 MW of baseload power (more in winter than in summer) , even without adding storage for firming. This is roughly what the last nuke they shut down had been supplying. And remember, this is just phase I of III, (with 1600 MW to be procured by 2027) and that output will likely peg to the nameplate numbers (~800MW for the first phase) during nor'easters, and close to that number at the beginning of deep cold snaps when grid demand is high.

The current fully legislated & signed off mandates for MA is now a total of 5,600 MW of offshore wind by 2030. That alone is enough power to drive multiple cc gas generators over the economic edge, and cover the planned nuke shutdowns within the ISO-NE grid. And that's just offshore wind, and just MA. Within the ISO-NE grid region both RI and CT are going for major offshore wind projects in the coming decade. CT is all-in for 2000MW, with ~1500MW already contracted-for. Tiny (by comparison of market size) RI has selected a contractor for one 400MW project, and another for a 132MW project. As stated previously, this party is just getting started, and it's not the only party in town- PV & batteries aren't going away- at utility scale PV + 4 hours of battery is currently cheaper than oil or gas peakers, even cheaper than the first tranche of offshore wind.

New York and New Jersey (outside of the ISO-NE grid) will also be building large amounts of offshore win d in the coming decade, but the cost of rooftop solar + batteries should be cheap enough to compete with the the regional residential retail pricing before 2035. The next couple of years will probably see the peak residential retail electricity prices here, but the crash in retail electricity prices could be sooner & faster than even I think, especially if driven by policy measures (or technological breakthroughs on PV &/or batteries.) Electric cars and smart car chargers can do a heluva lot of grid stabilization even if not sourcing power to the grid. By the time PV + wind get built to 3-4x the current annual energy requirements (the economic sweet spot, per Think-X analysis' that is cheaper than business as usual) the business models of the grid & power generation operators will be due for major overhaul.

Though not currently legislated & mandated, the current administration in RI has set a goal of 100% renewables for the state by 2040. But with or without policy drivers, it may reach that before then, given the cost learning curve of PV & batteries.

This has drifted well away the original topic of the thread, but given the market & policy trends I'm finding it ever harder to recommend oil or gas burning space heating or water heaters. Heat pump water heaters are now a mature product type, and within the warranty period the operational costs are likely to be cheaper than a gas burner, even without factoring in maintenance & installation costs.
 

Reach4

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This has drifted well away the original topic of the thread, but given the market & policy trends I'm finding it ever harder to recommend oil or gas burning space heating or water heaters.
Electricity works most of the time.
Gas works all of the time, in my experience, and can power a home generator, which I don't have. But I do have a gas heater and range that work without electricity. My WH works without AC power, tho that identifies it as one that is less efficient.
 

Dana

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Electricity works most of the time.
Gas works all of the time, in my experience, and can power a home generator, which I don't have. But I do have a gas heater and range that work without electricity. My WH works without AC power, tho that identifies it as one that is less efficient.

In New England gas only keeps working due to the capacity priority given to the space heating load over feeding gas power generators. But to meet firm MA state requirements on greenhouse gas emission levels going forward gas heating is going to cut way back over the next decade, and eventually go out of business.

My biz-partner just moved into a new house in a low grid-reliability neighborhood (a hazard of above-ground wires in a mature suburban forest), and got rid of the wood + oil dual-fuel heating system, installing a ground source heat pump (a 4 ton Waterfurnace Series 7) in it's stead, among multiple other upgrades to this circa 1960 house with a circa 1980s addition. Like others in his area he has a propane fired backup generator of sufficient size to run the whole house. A battery good for 4 hours of backup would have been similar money (less than 2x the upfront cost) , and he may even go there when he installs PV next year. As battery prices keep falling even a gas or propane generator may cease making financial sense in a decade or so. Using the EV battery as power backup for the house might be even more compelling after he trades in the Chevy Sierra for an EV pickup. That will not be happening until there is greater product selection and lower pricing on EV pickups in the US, but by the time his current truck is toast there will be something that affordably fills the bill.
 
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