Miami Green Homes


Looking at the Future – An inside report on a Florida Office Building fully powered by Solar Energy
April 5, 2013, 5:15 am
Filed under: Building knowledge, Energy Efficiency, Hot Topic, Resources

A guest post by Rush Hood, P.E., and Jeffrey J. Basiaga, Jr.

 

The “IEEE FWCS Industrial Tour Series” sponsored a tour of the Landmarc Construction Net Zero Energy Building in Tampa on March 28, 2013 hosted by Mr. Spencer Kass, Landmarc VP.   He has installed and is operating a practical, utility-connected, photovoltaic generation system. The office is approximately 2800 sq. ft. with lighting and HVAC fully within modern standards.  The building operates at “Net Zero” energy consumption and returns surplus energy to the electric grid.   There is an Electric Vehicle charging station installed and free EV-charging is provided to the visitors parked in the parking lot.

 

As with most engineering projects, there are many factors that are not obvious. A structural analysis  was performed on the building to ensure it could support the weight and wind loading of the solar panels. Special electrical equipment ensures the safety of utility workers by disconnecting the solar generation from the electrical service when the utility power fails. This feature prevents energizing the utility conductors when utility workers would expect them to be de-energized. Additionally, a clearly-marked switch enables easy disconnect of the building generation from the utility in an emergency. Further, the physical layout of the solar collectors must ensure that no portion of the panels are ever shaded by the building structure or trees, as any shading would have a disproportionate impact on the solar generation efficiency.

 

The electric metering functions are not obvious, either. The meter does not simply “run backwards” when the solar generation is supplying power to the utility, since the utility does not pay full “retail price” for energy generated by the customer. A special meter keeps separate track of energy consumed from and supplied to the utility. “Consumed kWh” and “Generated kWh” appear as separate line items on his electric bill. Of course, energy generated on-site that offsets simultaneous usage on-site effectively gives the customer “retail price” for these kWh.

 

Participants also discussed other cost and expense factors that impact the payback of the system, including maintenance, lightning damage, surge suppression, potential for weather damage, and vandalism and theft avoidance measures.  It turns out that the overall economic analysis of the project is very complicated, and at this time incomplete. The consensus of the participants, however, was that we were “Looking at the Future,” and we were all very impressed by the progress that has been made.

 

The engineers that toured the building were very grateful for the opportunity.  We encourage interested parties to seek, learn about, and promote the cutting edge & practical realizations of great ideas.

   

Rush Hood, P.E.,  is an Electrical Engineer and IEEE organizer rush.hood@ieee.org Jeffrey J. Basiaga, Jr., P.E., is an Electrical Engineer and IEEE organizer jb345@tampabay.rr.com



Water and wastewater (WWW) treatment – a look at the energy used for water in the US

While water and wastewater (WWW) treatment accounts for a surprising 5% of total U.S. electric power generation, topographically-variable WWW conveyance account for a more surprising 15% of the same total [Pod06; Coh04]. In addition, while wastewater contains energy in dilute form, current goals for recovering such energy represent only 0.02% of the total generation, through the use of microbial fuel cells of the future [Log04]. If, on the other hand, WWW were decentralized, up to 15% of total U.S. electric power production could be saved.

 

While centralization of WWW treatment was implemented to concentrate resources and ensure water quality, today many monitoring, quality control, and operation and maintenance (O&M) functions can be decentralized electronically. Imagine, if each building of the future contains a direct potable reuse system, then maintenance personnel, rather than driving to a central facility daily, would be dispatched electronically to neighborhoods for routine annual maintenance. Moreover, decentralization would increase the accountability of neighborhood residents in terms of responsible use of water, personal care products, and household chemicals.

 

Beyond energy savings, autonomous net-zero water (ANZW) buildings would not need to treat for most pesticides (US, 5 billion lbs/y) and industrial chemicals (US, 6 billion lbs/y), representing a total mass loading of 2 mg/L on U.S. surface and groundwater runoff. Treatment instead would focus on effective destruction of endocrine disrupting compounds (EDCs) such as pharmaceuticals, which cannot be as easily regulated in terms of environmental half-life as pesticides and other chemicals, by advanced oxidation. This latter advantage would address the current 6% feminization of male fish across all species (20%, black bass) in U.S. river basins [Hin09]. Finally, an urban demand for e.g. one million gallons of water every day in Southeast Florida would be removed from the (Everglades) natural system. Eliminated would be water rationing, and the need to treat seawater with total impurity levels two orders of magnitude higher than drinking water standards, to drinking water standards when impurities in treated wastewater e.g. in S. Florida currently meet 87 of the 93 numerical drinking water standards on average without further treatment.

 

Increased construction activity in the outlined areas over the last 10+ years. Many infill projects and zero lot line developments. Increased population growth in the target area with increased load (people) and demand (use per individual). Overall individual load has increased over X years by X gallons per day. Strain on water treatment system and infrastructure, especially close to water ways cited. Septic tanks systems that are undersized, outdated or broken, without eh owner knowledge. Purposeful (non permitted or documented) re-routing of sewage water to nearby water ways and excess burden on municipal sewer system with surface water runoff, increased rainfall intensity and more man-made diversions of water. Quantity of subsurface runoff (stormwater).

 

Estimates of water use in the United States indicate that about 410 billion gallons per day (Bgal/d) were withdrawn in 2005 for all categories summarized in this report. This total is slightly less than the estimate for 2000, and about 5 percent less than total withdrawals in the peak year of 1980. Freshwater withdrawals in 2005 were 349 Bgal/d, or 85 percent of the total freshwater and saline-water withdrawals. Fresh groundwater withdrawals of 79.6 Bgal/day in 2005 were about 5 percent less than in 2000, and fresh surface-water withdrawals of 270 Bgal/day were about the same as in 2000. Withdrawals for thermoelectric-power generation and irrigation, the two largest uses of water, have stabilized or decreased since 1980. Withdrawals for public-supply and domestic uses have increased steadily since estimates began. http://pubs.usgs.gov/circ/1344/



A look at Biofuel
June 26, 2012, 3:12 am
Filed under: Energy Efficiency, Hot Topic, Resources

Biofuel can be broken down into fuel made from plants. There are many forms; however, there are a few to focus on. Ethanol, Biodiesel, and Biomass have come to the forefront over the past 10 years, and have even caught the attention of the government. With increasing environmental concern, the government has shifted some focus to the creation and use of biofuel to take the strain off of fossil fuel use. In the U.S. alone, 138 million gallons of oil are consumed a year.

Ethanol is made from corn or sugar cane. It is utile is many different scenarios, from cars to airplanes. Most gas fuel nowadays is made with 10% ethanol, and is marked with an E10 on the pump. This make the gasoline around 6% less efficient than if it were solely gasoline. For airplanes, such as those used by Continental and Lufthansa, the fuel is 50% ethanol, and although it is better for the environment, it is 2.5 times more expensive. In the case of the airlines, it is solely for publicity and has no monetary benefit whatsoever. As previously mentioned, ethanol is made from corn or cane sugar. The process, however, is debated. Is takes three gallons of water to make one gallon of ethanol, and fossil fuels are used in the process as well. Although the process of refining corn into ethanol isn’t the most efficient, the amount of exhaust reaching the ozone is significantly smaller. Over the past ten years, this process has evolved to become more and more efficient and with time ethanol will prove to be a solid alternative to gasoline.

The main points politicians and environmentalists are making are that ethanol can be domestically produced, it is renewable, and it is cleaner burning than gasoline. Ethanol, when burned, releases up to 80% less toxins into the air, creating less pollution. The fact that ethanol can be produced domestically also helps to decrease its cost in that we are not paying for transportation from, say, the middle east.

A company in Wyoming called KL Process Design Group is now using woodchips instead of corn to product ethanol. It is believed that the waste to fuel industry will become stronger than the crop to fuel industry.

Other forms of biofuel are biodiesel, made from vegetable oil, and biomass, made from burning plant or tree matter to generate electricity. This process is very common throughout California, Maine, and Michigan.

The biofuel industry has created a much greater demand for crops in the United States, as 33% of the U.S. corn crop goes to ethanol production, and in doing so, the farming industry has become a stronger force. With this great demand, American farmers have seen much improvement in their earnings. But this also comes at a cost. With a third of the corn crop being dedicated to fuel production, the price for corn has increased, as well as many others. So what is better? Planting corn for fuel, or planting corn for food? This debate has been rallied all over the world, as European countries follow suit. Ethanol uses a lot of water, and a lot of crop to create little product, but the positive effects the change to ethanol provides for the environment as the rest of the worlds fossil fuels and resources has over the past ten years overshadowed the increase in price of corn.

The environment has become a central concern of the government as well as the people, so with these fuel processes evolving over time, the negative effects and consequences of biofuel production will eventually reach next to nothing.



Water Heaters: Solar versus On Demand/tankless
June 18, 2012, 10:55 pm
Filed under: Energy Efficiency, Materials, Resources, Sustainable Living, Water Efficiency

www.energysavers.gov/your_home/water_heating/index.cfm/mytopic=12850

www.energysavers.gov/your_home/water_heating/index.cfm/mytopic=12860

Solar water heaters have been replacing gas water heaters over the past ten years at a rapid pace. Consumer interest in them is not solely for the tax credits, but also for their economic payback with cheaper bills and startup costs.

The pros and cons for gas and solar water heaters are lengthy so there are a few things one needs to know when weighing the idea of solar. Solar powered heaters come in many different forms but typically consist of a collector and a heater.

There are three different types of collectors:

-Flat Plate Collector- This collector is an insulated and weatherproof box with a dark absorber plate underneath glass or plastic covers. They are similar to those used to heat swimming pools.

-Integral Collector Store Systems-These are also known as ICS or batch systems. They are made up of black storage tanks and tubes in a similar insulated box. Cold water passes through the solar collector first, heating up the water just a little, and then proceeds on to the backup water heater. This keeps a consistent source of hot water, and is more reliable. However, they are not good in cold climates as the tubes could freeze.

-Evacuated Tube Solar Collectors- These are made up of rows of clear glass tubes. Each tube has a metal absorber tubs which absorbs solar energy but inhibits radiant heat loss.

There are two types of active solar water heating systems:

-Direct Circulation Systems- pumps circulate household water through the collectors and into the home. This does not work in freezing climates.

-Indirect Circulation Systems- The pumps use a heat-transfer liquid and a heat exchanger. They are better for freezing temperatures.

 

 

 

 

 

 

 

 

 

Passive solar water heating systems tend to be less expensive and more reliable than active systems, but they are less efficient as well.

-Integral Collector Storage Passive Systems- This systems does not work well in freezing climates. They are very efficient with daytime and nighttime hot-water.

-Thermosyphon Systems- With this system, water flows through the system when warm water rises as cooler water sinks. These are less expensive than the previously mentioned passive system. The storage tank is heavy, however, so the contractor has to pay special attention to the roof of the home.

 

 

 

 

 

 

 

 

 

After learning a little bit about how the solar water heater systems work, it is important to weigh the pros and cons.

These systems range from $1,500 to $3,500. Gas systems cost between $150 and $450. This difference in price is significant and one must also consider the installation costs of the solar system which can run up to $2,000 plus regular maintenance costs.

Having explained costs, the solar systems last around the same as the gas systems yet they’re payback happens in four to eight years when you weigh gas vs. electrical bills. This means that within four to eight years, it is as though you are not paying for hot water anymore.

Another bonus can be found in tax credits. For any system installed after December 31, 2008, there is no maximum to the possible tax credit. Energy Star also has their own line of solar water heaters, which provides a full line of commercial and domestic energy efficient products.

Solar water heaters are not all mighty, however, and do have their fair share of negatives. For starters, the maximum water temperature that can be reached is lower than that of a regular on-demand system and the heating process tends to be slower.

The reliance on weather also provides a hurdle as the unit needs sunlight to produce the hot water. Many of the newer systems have a backup system to negate this.

One of the biggest concerns is their water storage tank. These can get quite large and if a contractor does not install them properly, there is risk of the roof getting damaged, as well as the interior of the home.

All of the negative aside, solar powered water heaters prove to be an economically feasible and friendly option for homeowners who plan to stay in the same home for an extended period of time and reap the benefits of the payback.



A Green “Home Away From Home”

Becoming environmentally conscious has emerged as a main concern of homeowners, business owners, and the government over the past decade. Green homes, with lower potable water consumption, less energy use, and better building materials are sprouting up all over the world and commercial businesses are following their lead. All of the basics of sustainability easily transfer from one building type, making the possibility for green hotels possible.

  1. Form an environmental committee- This committee will develop a plan for energy, water, and solid waste use.
  2. Monitor electric, water, gas, and waste usage- This should be done monthly and annually. This will also help the hotel determine which of the following should be addressed first and in what order.
  3. Install digital thermostats in hotel rooms and throughout hotel and replace incandescent light bulbs with compact fluorescents- These two go hand-in-hand. It is a matter of simple installation. Using the CFL bulbs saves on energy costs, as well as using the digital thermostat. Many hotels inEuropeare using a technique to limit use of air systems and light by requiring that the key card be put in an activation port in order for the lights to be on. This means that when the patron leaves the hotel room and takes their key card out of the port, the lights and air turn off and remain off until the patron returns and put the key card back in the port.
  4. Implement towel reuse program- Many hotels have begun using this technique to save on laundry water used. By hanging up the towel after use, the patron is indicating they will reuse their towel. If the towel is on the ground, housekeeping is expected to remove and wash the towel. For guests staying at a hotel for more than one night, it makes sense to save the towel and wait until it has been used more than once before placing it on the floor to be replaced by a clean one.
  5. Install 2.5-gpm (gallons per minute) showerheads or less in all guestrooms and employee shower areas- Low-GPM shower heads conserve a lot of water and in a building like a hotel where showering can occur every minute of the day, these shower heads work to decrease water used significantly.
  6. Install 1.6-gallon toilets in all guestrooms- Switching from a standard to a low flow toilet can save thousands of gallons of water per year. There are also toilets with two different flush options, one of which cycles out the water, the other flushes all waste.
  7. Implement a recycling program, for light bulbs, batteries, etc.
  8. Purchase Energy Star appliances- These could be the washer and dryer used for sheets and towels, dishwashers, refrigerators, televisions, air conditioners, and much more. A complete list of Energy Star products can be found at: http://www.energystar.gov/index.cfm?c=products.pr_find_es_products
  9. All office paper products should have 20% or more post-consumer recycled content

These many different ideas for going green in a hotel environment also apply to green homes, office buildings, schools, and healthcare. The basic ingredients to saving energy require making small changes, whose payoffs can be great in the long run. Hotels require large maintenance and energy costs, and even if going green isn’t the main concern, these methods save money, allowing for lower operating costs.

(SE, EB, edit JLD)



Insulation – a key component for energy efficient green buildings.
August 15, 2011, 7:14 pm
Filed under: Air Quality, Building knowledge, Energy Efficiency

Insulation is one of the most important aspects to consider when looking at the energy performance and potential savings for your project. Especially on residential projects, the standard code required insulation is quite insufficient and leaves much room for improvement.

When thinking about improved energy improvement and especially the introduction of alternative or renewable energy, insulation is key as most of the energy is lost at the envelope of the building: the roof and the walls. If a building has an energy consumption of 100 units and produces 60 units with alternative energy, there are still 40 units to be paid each month.
Insulation, very high efficient appliances and HVAC as well energy star rated doors and windows can bring the unit use to 50. Not the same 60 units created actually pay back the owner… insulation is the key to make this equation work.

Beyond energy savings, choosing the right insulation may also contribute to better air quality. Even though most of the particles find their way into the air during construction, some insulation, such as batt insulation used for energy or sound barriers, can easily be released through simple repairs or even installation of picture nails and hooks.

There are so many options these days to look at insulation for the building. Bonded logic produces a series called Ultra Touch, which uses post-consumer blue jeans. Not just great insulation, but also bonus points for recycled content. Blow in cellulose insulation is formaldehyde and VOC free while diverting 300 tons of denim per month away form landfills. The R value can go up 30. Not a bad option (www.bondedlogic.com/ultratouch-cotton.htm).

Another fully sustainable alternative would be recycled wool, loose-fill insulation, such as the oregano shepherd line that provides up to r-4 per inch (www.oregonshepher.com).

There are more sustainable alternatives without going all the way to fully recycled or reclaimed materials. Formaldehyde free fiberglass comes in the traditionally familiar batt and roll variety with values from 11-38. Rigid foam panels also come in less toxic options, as does spray in insulation. Johns Manville and Owens Corning now offer environmental lines of product.

Personally I prefer a spray in system such as Icynene, Greenfiber or Certainteed. These systems use soy based or cellulose blows insulation that not just is easy t install and will literally fill the very last crack, but it also lets the access material be recycled on the spot, virtually eliminating any waste during construction.

It is important to seal all cracks, even if they are only a fraction of an inch. A small gap next to the insulation may appear minimal, but consider adding all those little cracks up to one large opening. This hole is typically about 3 square feet. Would you leave a 3 square feet hole in your wall? Probably not, so seal it. Knauf is a good option for these cracks as are other weatherization techniques.

When tackling your next project or upgrade, think of the insulation and realize quick savings in your energy bill. For further questions, contact your design professional. Sebastian Eilert Architecture. 786.556.3118 www.SebastianEilert.com



Water Issues – part II
August 11, 2011, 12:07 am
Filed under: Energy Efficiency, Hot Topic, Water Efficiency

Water remains my favorite and most important issue when addressing green building
concerns. It is certainly not the most important topic when looking at the
various certification checklists, like the USGBC LEED rating system. It finally
received a prerequisite in the last update, but is dwarfed in the overall point
scale by considerations for energy and materials.

Energy indeed has gotten a lot of attention in the last few months, especially the
concept of net-zero energy. The net zero concept is very appealing by taking
advantage of the existing infrastructure rather than having to create a full
independent power storage unit. Typically the consumption averages out to zero
over the term of a 12 month period.

The same concept can be used for the consumption of water; essentially creating an onsite
water filter systems. Water will not be able to quite be net zero, due to
evaporation and other environmental factors that are undoubtedly part of the
cleaning process. But a recycled water loop will probably be about 95%
effective. The remaining 5% can easily be made up by rain water or a well,
depending on the geographic location of the project.

The interesting part to me is the energy that is required to move and clean water.
By bringing this aspect of water use directly to the project, much energy can
be saved on the moving of water to and from the project and the reality of net
zero energy and water is much more realistic to attain.

Considering now, that in California for example about one third of the state’s energy is
used to clean and transport water, it does seem a little like putting the stick
before the carrot…

I am grateful to be part of a cutting research project at the University of Miami
that is addressing this very topic: The net zero water dorm. This project will
have move students into a retrofitted hall to be the live users of on-site
cleaned water – all water, from sinks, showers and toilets.

What can you do for your own project? Continue to focus on water reduction in daily
use and install conservation features in your renovation and new construction.
Dual flush toilets or even composting toilets are readily available. Low flow
shower heads and faucets are standard for all manufacturers and a rain
collection system such as simple rain barrel can be installed in any project.

Use the best suited system for water heating, be it on demand, solar or
conventional tank with a PV panel to power it. By using water intelligently,
the use of energy can also be reduced. Why not be the first house to clean your
own water?

Start your own water conserving project with http://www.SebastianEilert.com




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