Showing posts with label DHW. Show all posts
Showing posts with label DHW. Show all posts

Monday, May 13, 2013

NYC Clean Heat Destroys Property Values

PlaNYC Heating Oil Regulations are pushing buildings from #6 and #4 oil to #2 oil, natural gas, or biodiesel. Conversions are in full swing. Sadly, many of the buildings are suitable for renewable energy conversions which would produce far better results for the environment and for occupants, as well as better long-term financial results for owners. It says on the website that owners can apply for compliance waivers through NYC DEP. Owners should do this if their buildings are suitable and if they have the financial wherewithal to make that transition to a renewable solution. As long as a credible renewable solution can be found, owners are in fact placing a long-term hedge on their energy costs, and will do far better than they would going along with the conversions which the City is pushing. The typical 30% gains in efficiency are too easily wiped out by the next energy price hike.

Compound investment returns from energy independence through renewables

Not only are these conversions counterproductive as long as there is a renewable energy alternative, owners are being offered subsidized financing to make it easier to make the wrong decision, and destroy the asset value of their buildings. Having said that, there may be some buildings that realistically could not make a transition to renewable energy economically, but in many cases it is well within reach to do in buildings that are 40 units and up. (Size matters because of economies of scale). In the long run, this will produce a steady path to asset appreciation.
Presently we are in PlaNYC 2013, but it started in 2007 as Plan NYC 2030, and since then evolved to PlaNYC 2.0. Clearly this is an extraordinarily important plan, and it puts NYC in a very proactive stance with respect to climate change issues, but in this area of renewable energy, not nearly enough is being done. Most of that shortfall rests on the general confusion in our society that energy efficiency somehow is an additive phenomenon and would result in energy independence. In that context renewable energy is then relegated to a marginal role. If you were to actually do a long-term energy plan for a building, you would see this is not so, unless the building is not capable of a renewable conversion. Most of the buildings that burn #6 could do it.
The first issue is a choice of what energy system do I want? Do I make my energy (renewables) or buy my energy (subscription-based, gas, electric, oil). The two paths are to a large degree mutually exclusive, because of engineering interdependencies. One clear example, if I can go the renewable route and perhaps eventually eliminate gas for cooking, and most heating/cooling, I may be able to eventually do centralized HVAC, and choose very different replacement windows, etc.
Most importantly, the path to energy efficiency of my existing fossil fuel system is an investment in becoming a long-term consumer of gas or oil, or even biodiesel, so it is a customer retention program for the energy industry. In this case it is driven by the well intended reduction of CO2 and particulates emissions of gas versus oil, but as long as a renewable alternative exists, the latter would produce greater benefits in the long run. Successive investments in energy efficiency produce strongly diminishing returns, so a property owner paints himself into a corner financially. Once the transition to a renewable infrastructure can be made, the financial future of that building is assured, because subsequent investments will produce compounding results. The transition to renewable energy practically ensures building preservation, because of superior economic performance over time.

Underwriters risk collateral values by underwriting energy efficiency

If you check the website for NYC's Clean Heat program you will see energy efficiency as the sole qualification for subsidized financing. All the usual culprits are there, CPC, NYSERDA et al, many of whom have energy credentials, for this conversion effort is a subsidy to the energy industry to the detriment of building values. Underwriters should learn to test for the difference between energy independence (renewables) vs. energy efficiency of carbon-based energy systems, simply because of the issue of diminishing returns with the former, and compounding returns with the latter. Energy Efficiency loans are riskier than Energy Independence loans, by far. To lump them all into one category is bad for owners and bad for underwriters. Building values for buildings that are 50% or better energy independent would rise strongly over the life of the mortgage, compared to buildings that invested in energy efficiency alone.

DaBx PlaNYC 2020: the Energy independence plan

Energy Independence
Windspeeds over NYC are higher than Chicago
With my consulting company DaBx Demand Side Solutions, we offered an alternative model to Mayor Bloomberg on July 4th 2011, which would achieve better results, and faster than the mere conversion from #6 to natural gas, and, as noted above, better financial outcomes for building owners. The plan is within reach for probably at least 50% of the building stock that is now converting to natural gas. It is more capital-intensive at first, but not much so once you evaluate it against the alternative of the forced gas conversion. The outcomes for air quality and building preservation would be far superior, not to mention public safety and national security. The conversion to gas only seems easier and cheaper in the short run, it is not if you do a 30 year energy plan for a building.
The basic model is based on understanding that in C and D class apartment buildings that are usually only 6 stories high, the old steam boilers usually provide Domestic Hot Water (DHW) through a coil in the boiler, and 30-50% of BTU output of those boilers goes to DHW. In those cases, economically feasible solutions can start from providing DHW with renewable energy, either geothermal or solar thermal. This eliminates 25-50% of CO2 and particulates emissions right away, it also gives the boilers the summer off, so it extends their useful life, and then at the time when the boiler dies from natural causes, the conversion to renewable HVAC can be completed. And yes, the famous split incentive between landlords and tenants needs to be cured.

Energy independence, wind and geothermal energy

Energy independence of buildings means the building stays lit during an outage, even if only partially. The two technologies that have been underappreciated so far are geothermal and wind power. In 2008 the press practically ridiculed Mayor Bloomberg about his advocacy for wind power on buildings, but they did not understand that specific wind turbines for buildings where just starting to come to market, and the Mayor was right on target, perhaps without knowing it. Average wind speeds around NYC are higher than in Chicago, supposedly the windy city. Moreover, around buildings, wind speeds pick up dramatically, offering excellent opportunities for wind power especially in the city.
Geothermal is the most strategic technology of them all, and City Hall is only just now starting to research it. Basically a geothermal system gives you a 400% gain in BTUs, and most importantly it can act as energy storage, besides providing domestic hot water. Here is one place where compounding returns come in, for energy storage is the single biggest problem in renewable energy, but DHW ends up acting as energy storage for your building. Unfortunately most existing geothermal systems in apartment buildings were wrongly designed, as DHW only, and not for energy harvesting. Buildings need 30 year energy plans, not point solutions.
Conclusion:
PlaNYC can be much more successful if the confusion between energy efficiency and energy independence through renewables is eliminated. Better outcomes for building preservation, air quality, and economic competitiveness of the city would result. Energy efficiency of a building with a carbon-based energy system is financially inferior and prolongs the period of CO2 emissions, energy independence through renewables reduces CO2 faster.

Sunday, May 2, 2010

The Geothermal DHW Dimension

One of the most strategic renewable energy components in residential living, and even more so in multi-family buildings is no doubt geothermal hot water (DHW). The reason is simple, everyone needs hot water for domestic purposes, and simple hot water tanks allow the water (and thus the heat) to be stored for later use, with minimal loss, and energy storage is the holy grail for the smart grid. Solar thermal is a superior solution for that reason also, because it is capable of far higher energy density than PV, but also because the storage problem is solved more easily in the form of DHW than it is with PV and batteries.

Unfortunately, manufacturers have a habit of living in silos circumscribed by their respective technologies, all the while pretending that their technologies are the solution to the exclusion of others. This creates the impression that e.g. geothermal DHW and Solar Thermal DHW are competitive solutions, when in fact they are potentially complementary, because of the extremely different behavioral characteristics of the technologies. Particularly, from the standpoint of designing energy generating systems, geothermal energy is base load capacity, i.e. within some limitations it can produce whenever you turn on the switch, whereas Solar and Wind power are peak load generating capacity, which are dependent on the weather, and thus may or may not produce when you turn on the switch. Therefore, solutions that are routinely presented as mutually exclusive, often are complementary instead.

As a result of the technology-centric approach, the field has been plagued by false tries, and in one extreme case a leading manufacturer of geothermal heat pumps, who is promoting their technology for the DHW application, in fact promotes a financial model for the application which leads to inherently wrong systems design. The problem here seems to be that the manufacturers should worry about what happens within their systems, and specifying the proper warranty specs, which become in effect minimum design standards, but NOT design specifications which should be engineered appropriate to the building not to the equipment. Building-centric design is the key. The answers are not the same for all buildings and all markets.

The unfortunate example alluded to here can be found at: Faulty Cost/Benefit Analysis for Earthlinked DHW Systems Designs which is a model apparently intended for design of geothermal DHW systems, but which cannot reliably predict the economic viability of such systems, and moreover makes the design error that generating DHW is the purpose of such systems, when in fact the storage of energy is much more important from the standpoint of designing renewable energy systems. The central problem of dealing with peakloads is how do I store the energy, and thanks to the constant demand for DHW in residential facilities, water storage allows us to harvest economical, renewable peak load power, or even off-peak power from the grid.

In a hybrid system, where the geothermal heatpump preheats the water typically to ca 100F, there is a backup source of heat, to take the water from 100F to the typical storage temperature of 140F (ASHRAE 12), and/or to serve as backup in case of failure. Therefore, preheating the water with geothermal heatpumps only makes sense as long as the cost per delivered BTU of the electricity which drives the heatpumps is lower than the cost per deliverd BTU of the fuel for the backup heating, these days most often Natural Gas. Therefore should the backup fuel be cheaper, it makes no sense to run the heatpump. Particularly when the cost of the two fuels move at different rates, this situation bears watching. Specifically gas is seasonally low in the summer when electricity is seaonally high, and the reverse happens in winter, when electricity is seasonally low, and gas seasonally high.

The model above uses an average for the two input costs, gas and electric in our example, wich is only usable in cases where the prices of the two fuels are far enough apart that the cost per delivered BTU cannot ever cross over, however, when the prices are in a narrow band, and do cross over seasonally, this model will give false indications of the savings that can be obtained by such a system, and if a false positive is used to design a system, the result will be a system which roughly saves money 9 months out of the year, and dis-saves money 3 months out of the year, and if the summer peak is bad enough, it could wipe out the savings of the other nine months. In short, such systems will fail, if they are rigidly based on such evidently false assumptions. Be that as it may, I've seen systems fail for these reasons, and get sold with entirely wrong predictions of their economic value, and in this case the manufacturer's patently faulty financial model is the cause of it.

Friday, April 30, 2010

Official Correspondence regarding Tank-less Hot Water Heaters

To the Secretary of Energy, Mr. Steven Chu:

quote

Subject: Misuse of Energy Star Label in "legititmate" applications
Date: Sun, 28 Mar 2010 09:09:24 -0300

Dear Mr. Chu:

Besides some of the outright hoaxes under the Energy Star label, there are occasionally problems of disastrous misuse of the label, which may seem perfectly legitimate on the surface.

Perhaps the biggest "legitimate" hoax under the Energy Star label is the oxymoron of a Tankless Hot Water Heater with Energy Star Rating, which qualifies for tax incentives to boot, but which positively undermines the
architecting of a renewable energy future.

The problem here is one of sub-optimization, and is in this case quite disastrous in nearly all applications of Hot Water Heaters. Namely, DHW storage is the cheapest most effective form of Energy Storage imaginable,
and switching to a tankless system is a ruinous decision from an energy management standpoint, since it means throwing out nearly "free" batteries, that would allow a property to harvest cheap energy, be it off-peak grid power, via time-of-use metering, or peak-load power such as wind or solar.

Conversely tankless water heaters may be quite valuable as backup power, in situations where renewable peak power is used, however in that case the Energy Star models should not be used, as they introduce needless maintenance issues if they only fire up a few times a year. So for that application, actually the non-energy star models are preferred, because they will last longer and are therefore dollar for dollar more effective and likely to be more reliable.

This issue is big enough that it deserves top level attention. There are geothermal heatpumps which can generate DHW with 400% efficiency, and as long as you design water storage large enough for intra-day use during peak power, you can run these off-peak on the grid, or alternatively with peak loads such as wind or solar, and have "free storage," and I'm using "free" advisedly, for the analytical point is that the water storage is cost justifiable from the DHW application alone.

Even large organizations, like NYC Housing Authority, have used stimulus funding to install tankless hot water heaters, and thus undermine their own long-term renewable energy future. It is time for this fallacy to stop.

Of course more generally there is always a risk of sub-optimization, if the attention becomes focused on the component level. Thus there is need for wide use of system-level Energy Star ratings, which could offset the
type of abuse of the rating here. It is too silly that stimulus money should be used to prolong the carbon intensive energy economy, instead of enabling the renewable energy future.
unquote

To which the unfortunate reply was:
quote

EXEC-2010-005700

Dear Rogier Fentener van Vlissingen,

Thank you for contacting the U.S. Department of Energy.  I understand you have concerns about ENERGY STAR qualified tankless hot water heaters.

ENERGY STAR is a joint program of the U.S. Department of Energy (DOE) and the U.S Environmental Protection Agency (EPA) designed to help all consumers save money and protect the environment through energy efficient products and practices.  In an effort to ensure that only products meeting the program requirements can receive an ENERGY STAR label, the EPA and DOE are further strengthening the certification process.  For an outline of these steps, please view:

ENERGY STAR
News and Announcements
EPA, DOE Announce Changes to Bolster ENERGY STAR Program (April 2010)
http://www.energystar.gov/index.cfm?c=news.nr_news&news_id=http://www.energystar.gov/cms/default/index.cfm?LinkServID=E77FB9F2-96D9-EAAD-6B3C6ECF0D9E4808#c_B4A3256E-188B-36F7-215E56FDB1D2450C

If you have further questions about ENERGY STAR product ratings, please contact ENERGY STAR directly through the contacts listed on the following web page:

ENERGY STAR
Contact Us
http://www.energystar.gov/index.cfm?c=contact.ct_index

You may be interested in reviewing rulemaking activities and regulations regarding energy efficiency for residential water heaters available through the DOE Office of Energy Efficiency and Renewable Energy’s (EERE) Building Technologies Program:

U.S. Department of Energy
Office of Energy Efficiency & Renewable Energy (EERE)
Building Technologies Program
Appliances & Commercial Equipment Standards
Residential Water Heaters
http://www.eere.energy.gov/buildings/appliance_standards/residential/waterheaters.html

The federal tax credits for energy efficiency are congressionally mandated. Products that qualify as a federal energy efficiency tax incentive were set forth in the Energy Policy Act of 2005. On October 3, 2008, former U.S. President George W. Bush signed into law the Emergency Economic Stabilization Act of 2008 to extend many of the energy efficiency tax incentives first enacted in 2005 that expired at the end of 2007, or that were scheduled to expire at the end of 2008. On February 17, 2009, Congress passed the American Recovery and Reinvestment Act of 2009 which includes several provisions modifying and expanding the scope of the energy efficiency and renewable energy incentives:

The Tax Incentives Assistance Project (TIAP) Legislative Language & Pending Updates
http://energytaxincentives.org/general/legislative.php

To inquire about possible changes to the list of eligible products, please contact your local congressperson.

For information on how energy related stimulus funds are being implemented in the state of New York, you may wish to contact your state energy office or view New York’s recovery website.  Below you will find your state’s energy office contact information as well as a link to your state’s Recovery Act website:

New York State Energy Research and Development Authority
Energy Efficiency Services
17 Columbia Circle
Albany, NY 12203-6399
Phone: (518) 862-1090
http://www.nyserda.org/

Recovery New York
http://www.recovery.ny.gov/

As you mentioned geothermal heat pumps, you may be interested in viewing  the following websites:

U.S. Department of Energy
Office of Energy Efficiency and Renewable Energy Energy Savers
Geothermal Heat Pumps
http://www.energysavers.gov/your_home/space_heating_cooling/index.cfm/mytopic=12640

Geothermal Heat Pump Consortium
The Consortium is a national non-profit trade association of the geothermal heat pump industry.
http://www.geoexchange.org/

U.S. Energy Information Administration (EIA)
Geothermal Heat Pumps
http://www.eia.doe.gov/cneaf/solar.renewables/page/heatpumps/heatpumps.html

Western Area Power Administration
Geothermal Heat Pumps
www.wapa.gov/es/pubs/fctsheet/GHP.pdf

Sincerely,

Amy Foster Parish
EERE Information Center
Office of Energy Efficiency & Renewable Energy (EERE)
U.S. Department of Energy
http://www.eere.energy.gov

unquote

Oh well, so off I go, now to write to the Energy Star program directly... to be continued.