Renewable Energy and Heat Pumps – Net Zero Energy by Design

As a mechanical engineer I spent 17 years in design of mechanical systems. Always seeking the best solution given budgets and adhering to efficient design principles. Often we can combine systems by hybridization, where two technologies come together in a synergistic match. I have used hybrid technologies, using ground loops and air-air fluid coolers, with heat pumps successfully in the mechanical design and construction of a number of buildings.

While wind energy may be harvested, it is not always available. Some regions get more wind than others, and there may be governmental or civic restrictions. For renewable energy, solar may be a better option than wind, even though it is only available during the day. In either case some form of auxiliary power will be required, such as batteries,  grid connection, fuel powered generator, or hydro-power.

The use of heat pumps allows for the provision of a number of heating and cooling devices which may be connected to a central circulating building loop. As heat pumps have operating temperatures generally between 40F to 90F, although it may vary depending on heat energy source, such as air, water or ground.  Air temperatures may vary during the day and season. As air temperature drops, heat pumps lose efficiency. We can see this in the following figure. (1)

air-source-heat-pumps-cold-weather

In the case of geothermal heat pump system design, there are some options. One method is to run a water source such as a pond, river, body of water in an open loop design,  in a closed loop method using an process waste heat stream or ground coupled system. Either system is usually connected to a heat-exchanger to which is connected a second closed house loop. The house loop is controlled to either discharge or gain heat from the geothermal loop.

I am attaching  a blog post (2) from 2007 where I made a comment in 2009. This blog post is still getting comments. I believe such systems can be designed and constructed and would contribute to a “Net-Zero” building systems.

I am a lawyer who has been interested in the subject of energy conservation since the seventies. Back when we had the first OPEC crisis, I thought this country would head in a direction away from the consumption of huge quantities of oil and gas. It didn’t happen. Now of course, our thirst for oil has been the primary reason for a preemptive war with no end in sight. Moreover, peak oil seems to be here. And so far nothing much seems to have changed. But the public, may at last be ready for something different.

There are some real promising things happening with new solar energy systems and with wind turbines. It is long past due. But I still keep wondering whether we are approaching this problem of solving our energy demands the right way. With both solar and wind systems all technology seems to be headed toward the creation of electricity. Electricity is definitely useful but often inefficient.

Heating and cooling costs are about 60-70 percent of home energy costs. It is far more cost effective to use heat transfer than to make heat. Water source heat pumps are 300-400 percent efficient while the best ordinary HVAC systems might be forty percent efficient. (Are they that much?) What if you could even vastly surpass the efficiency of a water source heat pump. How? By making the wind pump the water instead of an electric pump.

Why not use wind to its best advantage? Make the wind do what it has done very efficiently for hundreds of years: pump water. Make it pump water from a warm place to a cold place and make it store the heat where the heat is needed or wanted. In the winter pump the heat from under the ground into the house. In the summer pump the heat from house into the ground.

To do this, because of the wind’s variability, one would need a huge (?) thermal sink in the house to slowly release the heat transferred from underground to the heat sink or to transfer the heat from the house to the ground while the wind was not blowing.

A four part system. A wind turbine. A pump. A closed loop of pipe. An interior thermal sink.

It is fairly well known that in most climates, five or six feet below ground, the temperature is a about 55 degrees. I think it is quite possible to take advantage of the geothermal underground temperature by using a wind turbine to pump water from underground into an interior thermal sink. If a large enough volume of water could be circulated to where the interior heat sink reached 55 degrees, I think such a home’s heating and cooling costs would be drastically reduced.

If the large thermal sink could get the house temperature substantially raised in the winter and substantially cooled in the summer, very little additional energy might be required to bring it to a desirable temperature with the use of a water source heat pump. A water source heat pump would work in tandem very well by using the internal heat sink as a convenient source to operate a water source heat pump.

My idea would be to use a vertical wind turbine on the roof coupled to an Archimedes screw to pumps and circulates water through the closed loop. The vertical wind turbines seem to need less wind, have more torque, and are quieter. I also think that from an architectural point of view, they would look much more attractive, especially the ones that look like spinnerets. They also take advantage of a sloping roof which increases wind speed.

I also think the Archimedes screw would be an ideal pump. It requires no gears or lubrication and could attach by a straight shaft to the vertical wind turbine. An Archimedes screw would be very inexpensive as pumping systems go and extremely reliable as there is really nothing to break.

I have other ideas about roof design and about turbine design for greater efficiency. I also have ideas about the plumbing. What I would like to see is whether there are people out there who think this idea has commercial merit and if so, how we might go about making wind driven water pumping for geothermal transfer a success. We would need some engineering and architectural expertise and some ability to fabricate the wind turbines and pumps.

I look forward to responses.

Duane Tilden said…

I have been looking at the latest responses and it seems to me there is some confusion about this idea.

Firstly, heat pump technology, as pointed out achieves it’s high COP’s from the phase change. It is through the leveraging of the refrigerant phase change from a fluid to the gas phase where heat energy can be obtained from low temperature heat sources. This is how geothermal heat pumps can obtain heat energy from relatively low temp sources such as the ground where nominal ambient water temp would be at 55F and deliver hot water at temps of 90F to 140F.

Alternatively heat pumps can be used in air/air, air/water, water/air and water/water configurations. These are generally stand alone devices where in a properly engineered installation do not require supplemental heat sources.

Wind energy is a separate sustainable, environmentally friendly application. In my opinion the OP’s idea of using wind energy to move water around for a heat pump application is marginal and likely too capital intensive to realize any real benefit. Also, it is just too restrictive, in my opinion.

Wind energy converted directly to electricity, or other dedicated pumping applications where electricity is not available is best (water pumping up to a reservoir in agricultural or power generation schemes for example). There also may be some merit to the idea of storing the energy as compressed air, but the amount of heat generated would not be significant, usable heat source. Try heating your home with a candle.

Electricity is used by a wide range of applications, so why not use the wind energy to best effectiveness? The operation of the compressor in the heat pump and the pumps to run the water loop(s) require electricity, so do common home appliances.

There may be some applications where the proffered idea would make sense, but not likely widely applicable for single family residences unless you have a large property and money to burn.

SEPTEMBER 26, 2009 AT 10:44 PM

 

References:

  1. heat-pump-effective-temperature-range/
  2. wind-turbine-heat-pump-geothermal
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The BC Energy Step Code – Missing the Point

The BC Energy Step Code is currently being implemented in British Columbia as an answer to future energy considerations in new building construction. It achieves this claim of moving towards “Net Zero” building construction by utilizing a building envelope first approach with modeling and a performance test.

The idea is that by raising a building’s theoretical energy efficiency a building will become a net zero home. In the process, there is a requirement for a certified and licensed energy adviser to be involved in the modeling, construction and testing phases of the building. (1)

In conjunction with this approach is the claim that builders can construct these buildings being “fuel-neutral”. Using this rationale the roles of mechanical systems design, testing and commissioning are omitted in the performance considerations of the building.

However, a net-zero building must include the omitted systems as the design and operation of necessary systems. These may include the ventilation and exhaust systems, water heating, laundry, and heating systems. Also, rain-water collection for irrigation and gray water systems or other load reduction schemes may all may contribute to the energy consumption and success of a “net zero” building.

Some of these services will always be required in a municipal setting such as electrical, water and waste. Reduction strategies are advised as further increases in population will add additional loads at existing consumption rates which might overload existing supply and waste systems infrastructure such as pipes and cable.

The final answer to how a building performs will be in the overall utility bills paid by the building for its operation. This includes the electrical power, gas consumption, solid and liquid waste disposal and water supplied. Unless you live in a remote rural area where none of these services are provided by a municipality, there will always be a design component of the mechanical systems that contributes to the operation of an energy efficient home.

References:

  1. How the BC Energy Step Code Works

 

Turning to Net Zero for Buildings – The HERS Index

Over the last few months my time has been occupied with travel and work. Relocation and working in construction has consumed certain amounts of time. In the process I have continued to learn and observe my working environment from the perspective of a mechanical engineer.

I have upgraded some of my technology, investing in a smart phone for it’s utility and ease of connection. However, this newer tech is still not the best for longer term research and curation efforts, such as this blog. I am happy to report I have managed to land a longer term residence which now will provide me the needed stability and access to resources, while I can set up my work space needed for more intensive endeavours.

Now relocated in Vancouver, I have a few projects in the works, and am able to get back to focusing some of my time into my own research and development, to which, is one of the major purposes of my blogging. Next week, on September 25th there is a luncheon course presentation I plan on attending regarding upcoming changes to the BC Building Code introducing The Energy Step Code. More on this topic later after the seminar.

In California we already see the movement on towards the construction of net zero buildings, as compliance to the 2016 Building Energy Standard which applies to “new construction of, and additions and alterations to, residential and nonresidential buildings.” (1) These rules came into effect January 1st, 2017. I will be reviewing this publicly available document and provide more insight and commentary at a later time.

One measure of rating homes for energy efficiency that I have seen often referenced and may be a tool for reporting and rating homes is the HERS Index as shown in the graphic.

Image 1:  HERS Index scale of residential home energy consumption.

As we can see from the scale that there is reference home, so there are calculation needed to rate a home, computer methods are available online where a houses data can be input for a curious homeowner, however qualified ratings are to be done by a qualified HERS Rating technician. These ensure by performance tests that a house meets standards in actual use and perform as claimed.

A comprehensive
HERS home energy rating

The HERS Rater will do a comprehensive HERS home energy rating on your home to assess its energy performance. The energy rating will consist of a series of diagnostic tests using specialized equipment, such as a blower door test, duct leakage tester, combustion analyzer and infrared cameras. These tests will determine:

  • The amount and location of air leaks in the building envelope
  • The amount of leakage from HVAC distribution ducts
  • The effectiveness of insulation inside walls and ceilings
  • Any existing or potential combustion safety issues

Other variables that are taken into account include:

  • Floors over unconditioned spaces (like garages or cellars)
  • Attics, foundations and crawlspaces
  • Windows and doors, vents and ductwork
  • Water heating system and thermostats

Once the tests have been completed, a computerized simulation analysis utilizing RESNET Accredited Rating Software will be used to calculate a rating score on the HERS Index. (3)

As buildings become more expensive and are asked to provide ever more services there will be a movement to make these building more efficient to operate and maintain. As we do more with less, there will be social impacts and repercussions. To some these changes may be disruptive, while enabling newer markets in energy efficiency, renewables, energy storage, micro-grids and net zero buildings, to name a few.

References:

  1. California Building Code Title 24 – 2016 Building Energy Efficiency Standards for Residential and Nonresidential Buildings.
  2. Understanding the HERS Index
  3. How to Get a HERS® Index Score

High Efficiency Clothes Washers

Nowadays we are searching for more ways to be energy efficient at home, work and elsewhere.  Our resources are not infinite, even if they are renewable. And, as such, we should be seeking ways to reduce our energy and water consumption, not only to be a good citizen but also for the money it saves which can be utilized elsewhere.

Yesterday I did my laundry, packed all my smelly and soiled clothes in a plastic garbage and headed off to the laundromat in Canmore. I chose a double loader which cost $4 + another buck for the heavy soiled clothing option. Not sure how this thing worked, I bought two small boxes (it’s a double loader after all so two boxes should do, I thought) of Tide for a buck apiece.
Samsung WF210ANW High Efficiency Washer

Figure 1.  Image of a Samsung’s WF210 HE Washing Machine top loading washing machine. (1)

The instructions on the machine were not clear, so I opened the boxes and sprinkled them on my clothes, set the temp for warm and started the machine. It was a 30 min cycle, and after about 5 minutes I did not see any appreciable amount of water in the washer, also I noticed that there was a slot for the detergent. So, I decided to buy another box of detergent and put it into the pull out. The machine was on 10 minutes now, and still no water… wtf?

Image result for high efficiency washing machine

Figure 2.  Graphic comparing a HE washing machine to a traditional top loader. (2)

Okay, so I call the management which operated the local motel, informing them that the machine is broken, and a girl comes out to see what is going on. She assures me it’s fine and working, that the machine uses very little water. Okay, I am skeptical and concerned that with so much detergent and very little water my clothes would not get clean and be covered with a residue.

In the meantime a nice German lady comes over to me and says that she has never seen a top loader before and they only use front loading machines where she is from. I laughed and told her that in Canada we have a tendency to waste our resources as we have so much, whereas in Germany they have a larger population crammed in a small country. The government of Canada has a tendency to give lip service to energy and water efficiency.

The end result was that the clothes came out brilliantly clean with no residue. Most of the water was spun out and the clothes were only slightly damp, which meant that my dryer time was greatly reduced. The amount of heated water and energy used for drying is greatly reduced. Is it not time to get rid of the energy hogs?

 

References:

(1)  High Efficiency Washing Machines Save Money With Less Water, Energy

(2)  High Efficiency Washing Machine

Hybrid Electric Buildings; A New Frontier for Energy and Grids

.OneMaritimePlaza-300x225 PeakerPlantSanFranHybrid Electric Buildings are the latest in developments for packaged energy storage in buildings which offer several advantages including long-term operational cost savings. These buildings have the flexibility to combine several technologies and energy sources in with a large-scale integrated electric battery system to operate in a cost-effective manner.

San Francisco’s landmark skyscraper, One Maritime Plaza, will become the city’s first Hybrid Electric Building using Tesla Powerpack batteries. The groundbreaking technology upgrade by Advanced Microgrid Solutions (AMS) will lower costs, increase grid and building resiliency, and reduce the building’s demand for electricity from the sources that most negatively impact the environment.

Building owner Morgan Stanley Real Estate Investing hired San Francisco-based AMS to design, build, and operate the project. The 500 kilowatt/1,000 kilowatt-hour indoor battery system will provide One Maritime Plaza with the ability to store clean energy and control demand from the electric grid. The technology enables the building to shift from grid to battery power to conserve electricity in the same way a hybrid-electric car conserves gasoline. (1)

In addition to storage solutions these buildings can offer significant roof area to install solar panel modules and arrays to generate power during the day.  Areas where sunshine is plentiful and electricity rates are high, solar PV and storage combinations for commercial installations are economically attractive.

For utility management, these systems are ideal in expansion of the overall grid, as more micro-grids attach to the utility infrastructure overall supply and resiliency is improved.

In recent developments AMS has partnered with retailer Wal-Mart to provide on-site and “behind the meter” energy storage solutions for no upfront costs.

solar-panels-roof-puerto-rico.png

Figure 2.  Solar Panels on Roof of Wal-Mart, Corporate Headquarters, Puerto Rico (3)

On Tuesday, the San Francisco-based startup announced it is working with the retail giant to install behind-the-meter batteries at stores to balance on-site energy and provide megawatts of flexibility to utilities, starting with 40 megawatt-hours of projects at 27 Southern California locations.

Under the terms of the deal, “AMS will design, install and operate advanced energy storage systems” at the stores for no upfront cost, while providing grid services and on-site energy savings. The financing was made possible by partners such as Macquarie Capital, which pledged $200 million to the startup’s pipeline last year.

For Wal-Mart, the systems bring the ability to shave expensive peaks, smooth out imbalances in on-site generation and consumption, and help it meet a goal of powering half of its operations with renewable energy by 2025. Advanced Microgrid Solutions will manage its batteries in conjunction with building load — as well as on-site solar or other generation — to create what it calls a “hybrid electric building” able to keep its own energy costs to a minimum, while retaining flexibility for utility needs.

The utility in this case is Southern California Edison, a long-time AMS partner, which “will be able to tap into these advanced energy storage systems to reduce demand on the grid as part of SCE’s groundbreaking grid modernization project,” according to Tuesday’s statement. This references the utility’s multibillion-dollar grid modernization plan, which is now before state regulators.  (2)

References:

  1. San Francisco’s First Hybrid Electric Building – Facility Executive, June 28, 2016
    https://facilityexecutive.com/2016/06/skyscraper-will-be-san-franciscos-first-hybrid-electric-building/

  2. Wal-Mart, Advanced Microgrid Solutions to Turn Big-Box Stores Into Hybrid Electric Buildings, GreenTech Media, April 11, 2017  https://www.greentechmedia.com/articles/read/wal-mart-to-turn-big-box-stores-into-hybrid-electric-buildings?utm_source=Daily&utm_medium=Newsletter&utm_campaign=GTMDaily

  3. Solar Panels on Wal-Mart Roof  http://corporate.walmart.com/_news_/photos/solar-panels-roof-puerto-rico

An Engineer’s Take On Major Climate Change

Summary:
1. Climate science is very complicated and very far from being settled.

2. Earth’s climate is overwhelmingly dominated by negative-feedbacks that are currently poorly represented in our Modeling efforts and not sufficiently part of ongoing investigations.

3. Climate warming drives atmospheric CO2 upward as it stimulates all natural sources of CO2 emission. Climate cooling drives atmospheric CO2 downward.

4. Massive yet delayed thermal modulations to the dissolved CO2 content of the oceans is what ultimately drives and dominates the modulations to atmospheric CO2.

5. The current spike in atmospheric CO2 is largely natural (~98%). i.e. Of the 100ppm increase we have seen recently (going from 280 to 380ppm), the move from 280 to 378ppm is natural while the last bit from 378 to 380ppm is rightfully anthropogenic.

6. The current spike in atmospheric CO2 would most likely be larger than now observed if human beings had never evolved. The additional CO2 contribution from insects and microbes (and mammalia for that matter) would most likely have produced a greater current spike in atmospheric CO2.

7. Atmospheric CO2 has a tertiary to non-existent impact on the instigation and amplification of climate change. CO2 is not pivotal. Modulations to atmospheric CO2 are the effect of climate change and not the cause.

Watts Up With That?

Guest essay by Ronald D. Voisin

Let’s examine, at a high and salient level, the positive-feedback Anthropogenic Global Warming, Green-House-Gas Heating Effect (AGW-GHGHE) with its supposed pivotal role for CO2. The thinking is that a small increase in atmospheric CO2 will trigger a large increase in atmospheric Green-House-Gas water vapor. And then the combination of these two enhanced atmospheric constituents will lead to run-away, or at least appreciable and unprecedented – often characterized as catastrophic – global warming.

This theory relies entirely on a powerful positive-feedback and overriding (pivotal) role for CO2. It further assumes that rising atmospheric CO2 is largely or even entirely anthropogenic. Both of these points are individually and fundamentally required at the basis of alarm. Yet neither of them is in evidence whatsoever. And neither of them is even remotely true. CO2 is not only “not pivotal” but it…

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Water Conservation and a Change in Climate Ends California Drought

Water scarcity is becoming a greater problem in our world as human demands for water increases due to population growth, industry, agriculture, and energy production. When the water supply is being pushed beyond its natural limits disaster may occur.  For California residents the end of the drought is good news.  Return of wet weather raises reservoir levels and effectively prevents wildfires.  However, another drought could be around the corner in years to come.  Thus government and water users need to remain vigilant and continue to seek ways to conserve and reduce water use.
ca-reservoirs 2017 End of drought.png
Figure 1. 2017 California Major Water Reservoir Levels
By Bark Gomez and Yasemin Saplakoglu, Bay Area News Group (1)
Friday, April 07, 2017 05:17PM

Gov. Jerry Brown declared an end to California’s historic drought Friday, lifting emergency orders that had forced residents to stop running sprinklers as often and encouraged them to rip out thirsty lawns during the state’s driest four-year period on record.

The drought strained native fish that migrate up rivers and forced farmers in the nation’s leading agricultural state to rely heavily on groundwater, with some tearing out orchards. It also dried up wells, forcing hundreds of families in rural areas to drink bottled water and bathe from buckets.

Brown declared the drought emergency in 2014, and officials later ordered mandatory conservation for the first time in state history. Regulators last year relaxed the rules after a rainfall was close to normal.

But monster storms this winter erased nearly all signs of drought, blanketing the Sierra Nevada with deep snow, California’s key water source, and boosting reservoirs.

“This drought emergency is over, but the next drought could be around the corner,” Brown said in a statement. “Conservation must remain a way of life.” (2)

References:

  1. https://wattsupwiththat.com/2017/04/08/what-permanent-drought-california-governor-officially-declares-end-to-drought-emergency/ 
  2. http://abc7news.com/weather/governor-ends-drought-state-of-emergency-in-most-of-ca/1846410/

What Does Moist Enthalpy Tell Us?

“In terms of assessing trends in globally-averaged surface air temperature as a metric to diagnose the radiative equilibrium of the Earth, the neglect of using moist enthalpy, therefore, necessarily produces an inaccurate metric, since the water vapor content of the surface air will generally have different temporal variability and trends than the air temperature.”

Climate Science: Roger Pielke Sr.

In our blog of July 11, we introduced the concept of moist enthalpy (see also Pielke, R.A. Sr., C. Davey, and J. Morgan, 2004: Assessing “global warming” with surface heat content. Eos, 85, No. 21, 210-211. ). This is an important climate change metric, since it illustrates why surface air temperature alone is inadequate to monitor trends of surface heating and cooling. Heat is measured in units of Joules. Degrees Celsius is an incomplete metric of heat.

Surface air moist enthalpy does capture the proper measure of heat. It is defined as CpT + Lq where Cp is the heat capacity of air at constant pressure, T is air temperature, L is the latent heat of phase change of water vapor, and q is the specific humidity of air. T is what we measure with a thermometer, while q is derived by measuring the wet bulb temperature (or, alternatively, dewpoint…

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California adopts nation’s first energy-efficiency rules for computers

The California Energy Commission has passed energy-efficiency standards for computers and monitors in an effort to reduce power costs, becoming the first state in the nation to adopt such rules. Th…

Source: California adopts nation’s first energy-efficiency rules for computers

Aluminum Metal Advancements in Sustainability

Can the idea of sustainability be determined by metrics?  The answer is “Of course”, as any type of improvement can be measured. We understand it is far more efficient to recycle aluminum than it is to produce it the first time, which we call this value embodied energy.  However, since refining represents a significant proportion of manufactured costs there becomes a premium on recycling used aluminum.  Not only are the savings in energy, they are also in emissions of GHG’s.

Novelis reports.

“Recycling aluminum produces 95 percent fewer greenhouse gas (GHG) emissions and requires 95 percent less energy than primary aluminum production, enabling Novelis to achieve lower GHG emissions despite increasing global production capacity.” (1)

Novelis also reports improvements in Energy Intensity and Water Intensity metrics.

Significant gains were also made in fiscal 2016 as it relates to water and energy intensity. Novelis achieved a 22 percent reduction in water intensity and a 24 percent reduction in energy intensity for the 2007-2009 baseline.  (1)

Novelis Core Business

Novelis produces close to 20 percent of the world’s rolled aluminum products and we are strategically located on the four continents where aluminum demand is the greatest: North America, South America, Europe and Asia. Our dedication, innovation and leadership have made us the number one producer of rolled aluminum in Europe and South America, and the number two producer in North America and Asia. We also are the world’s largest recycler of used beverage cans, which comprise a critical input to our operations. Quite simply, recycling is a core element of our manufacturing process.  (2)

Figure 1:  Novelis Opens World’s Largest Aluminium Recycling Facility (3)

Novelis has officially opened the “world’s largest” aluminium recycling centre located adjacent to the company’s rolling mill in Nachterstedt, Germany and costing over £155m.

The recycling centre will process up to 400,000 metric tons of aluminium scrap annually, turning it back into high-value aluminium ingots to feed the company’s European manufacturing network.

“The Nachterstedt Recycling Centre is a significant step toward our goal to be the world’s low-carbon aluminium sheet producer, shifting our business model from a traditional linear approach to an increasingly closed-loop model,” said Phil Martens, president and chief executive officer of Novelis.  (3)

References:

(1) http://www.prnewswire.com/news-releases/novelis-reports-significant-gains-in-sustainability-300379847.html

(2) http://novelis.com/about-us/assets-and-capabilities/

(3) http://www.ciwm-journal.co.uk/novelis-opens-worlds-largest-aluminium-recycling-facility/

Related Posts:

Embodied Energy https://duanetilden.com/2014/12/10/embodied-energy-a-measure-of-sustainability-in-buildings-construction/

Energy Efficiency  https://duanetilden.com/2016/06/19/measuring-and-monitoring-energy-efficiency/