If you go with any sort of solar system, make sure it has a gas backup and not electric. My energy costs went up $100/month when I added our solar system down here in San Diego. I am now getting it corrected with the installation of a small gas tankless unit, using the solar storage system as a pre-heater. If you're building the home then many of the traditional drawbacks of tankless don't apply to you. You can build in the correct gas line and venting from the start. If I were in your shoes I'd probably go tankless (30 percent tax credit this year -- see the stimulus law or visit www.energystar.gov). If a single unit won't handle your demand then get two. And plumb it with the small tank system (10 gallon) for recirculation and to overcome any sandwich problems. This approach has been detailed in this forum somewhere.

Guys if you read the post, the reason the tank water heater was so expensive was due to the construction required to get his house up to code. I personally like my tank heater. If your changing from a tank to tankless there is alot of work to do. Moving water lines, moving gas lines (possibly upgrading gas line size too) and running a new intake/exhaust if using gas, upgrading the main service amps if using electric. Some things to consider Tank Heater Pros Costs less to replace in the future Easier to maintain (Tank water heaters are easy to flush out every year) Easier to install (dont have to upgrade gas line or main service amps) Gas water heater will still operate in power outage (electric will still have some hot water to use for a while till power kicks back on). Cons Not as efficient as tankless No Tax Credits Hot water limited by FHR (first hour rating) Tankless Heater Pros Unlimited hot water More efficient Saves space Cons Will cost more in the future to replace (there is no guarantee the tankless will last longer than a tank version, the heat exchanger can go bad and that is the most expensive part of the tankless) , Harder to maintain (you need to try to clean those tankless heaters out every year with a descaler so they stay working efficiently) Harder to install (upgrade gas line or main service amps) Tankless heaters have a limited throughoutput. While it is unlimited hot water, it can only supply so many gallons of hot water at a time Will not operate in a power outage. A tankless water heater is controlled by electronics whether the heater is gas or electric does not matter. Requires minimum gallons per minute from city water supply, some people have not been able to install due to that problem. Consumer reports note that users complain of inconsistant water temperatures. http://www.consumerreports.org/cro/appliances/heating-cooling-and-air/water-heaters/tankless-water-heaters/overview/tankless-water-heaters-ov.htm Another good site to look at: http://www.waterheaterrescue.com/pages/WHRpages/English/Longevity/tankless-water-heaters.html

You asked what we thought of the quote: The quote includes a "descaler" . I have no solid information on what that is... but I suspect it's a completely bogus piece of equipment. It's not a water softener. If you have hard water do yourself a favor and skip the "descaler" and buy a water softener. Don't bother with any tankless unit that is significantly less than 200k btu input (they are usually 198-199k) I installed tankless units in my last two houses. I've run the numbers backwards and forwards. They will save $80-100 a year in operating costs. If you hire someone to clean them, particularly if you have hard water and no softener, and do that every 12-24 months, it will eat up all of your savings. If you clean it yourself, esp if you have soft water so you are cleaning it every 24-36 months, it's a minor deal. Don't buy a tankless only because it will save you money. It's difficult to recoup the install costs in a reasonable amount of time. Do buy a tankless if you want to save space, want continuous hot water and also appreciate saving $100 a year. The most economical to install and operate is a hybrid tank heater. The payback on that is good, there are big rebates and you get cooling / dehumidification.

Funny to be accused of evangelism by poster that incited an "Amen", a few posts up :) Always appreciate feedback and constantly working on preachiness of writing style. I think including links or reading opines without sourcing helps others decide on misleading comments. It looks like Stiebel updated their Accelera HPWH to include an electronic control screen since we bought one a couple years ago for parents house. After an updated check on reviews I still feel safer with Accelera but it's hard without knowing volume of units sold. Surely Rheem has sold more HPWH than Stiebel at this point, despite Accelera being around longer. Reliability is a compelling reason to go with Rheem Marathon an electric resistance tank. Best warranty and most well-reviewed water heater available. Tank size plays a role here too. Bigger tank means better hot water performance, with minor hit in efficiency. The bigger the tank, the better for grid storage and demand control. Demand control has been around a long time with the most basic strategy using a timer and time-of-use billing options through utility. Studies will continue forever on more advanced grid-smart water heating technology but at this point, it's a time-tested technique with this smart water heater article quoting up to one million in use already with potential savings for homeowners and grid. Another article from same site points to irony of battle between grid storage potential of simple electric resistance tanks and the efficiency of heat pump water heaters. In that first article the Hidden Battery link seemed misdirected but it was put out by the NRDC pointing to potential of electric tanks to reduce the need of new power plants and grid storage for renewables. Large, reliable electric resistance tanks are becoming more of an asset while gas is becoming more of a liability. I think most of this forum's posts could be described as meaningless or feel-good-only but definitely not water heating. It has large environmental and social consequences. It's one of the only home purchases capable of beating the stock market for returns on investment. I think the ROI currently lies with HPWH but the second best choice could easily be a good ole electric tank. If an electric utility offers good incentives, electric tanks like the Marathon, could beat tankless gas or HPWH in total lifetime costs including repairs and replacement. A home equipped with PV panels and Marathon tank could also be in the running as best long-term water heating investment.