Energy efficiency and production
Energy independence is the first of many key pillars to our resilient home and the development of personal responsibility platform. One of the unique reasons we choose to build this home in Jensen Beach, Florida (Climate zone 2) is the fact that it could one of the most difficult places in the nation to build a Net ZERO home. The reason lies in MULTIPLE major hurdles that need to be overcome simultaneously:
- Radiating heat – Extended periods of hot radiating heat requires large amounts energy for mechanical cooling
- High humidity – requires larges amount of energy for mechanical de-humidification
- Minimal daily temperature variation – no opportunity to capture and store thermal energy
- Clouds – cloud coverage reduces daily solar production by 25% over a sunny location like Southern California or Southwest USA.
- Restrictive electrical regulations
- Outdated gray water recycling regulations
- Restrictive rainwater harvesting regulations
In order to accomplish this independence we used the following strategies:
- Be as efficient as possible in order to reduce the need for energy.
- When you do need energy make sure the equipment being used is the most efficient as possible for the time it is used.
- DC-microgrid to increase the resiliency of the home and increase the efficiency on a site and community level
- Be able to see what you are using when you are using it in order to actively manage consumption real time.
To succeed in our strategy we needed to address the following:
- building efficiency – eliminate thermal bridging
- manage energy consumption
- monitor energy
As we were looking to develop a Zero Net Energy home, I knew the secret to obtaining this goal would start in the design phase of the home beginning with the guts (the industry now calls it the envelope – and in particular a high performance envelope), the electrical systems, the management systems and then the actual production of alternative energy. Our design strategy started with the philosophy of “elimination” – eliminate then no need. First was to incorporate “Passive energy” design into our plans in order to reduce our electrical requirements. This entails the use of shading and building alignment in regards to the sun and other techniques (natural light in all rooms reduces the need for artificial lighting) that utilize everything nature can offer in order to reduce the demand for energy. Secondly we looked to incorporate a “Passive Moisture” design strategy. Here we will review all materials used in the construction of the exterior and interior and insure they do not absorb moisture when the home is open and exposed to exterior moisture. Wood when used as interior walls, furring strips on exterior walls, trusses (roof and floor), and flooring all act like sponges for moisture. Once these little sponges are full of water, it takes a lot of energy to remove it. In many instances mechanical equipment does not or is not capable of removing the moisture – particularly in wall cavities, and the home experiences mold growth and in many cases black mold. The envelope of choice will not use or minimize the use of materials that act like “little sponges”. Proper space to space ventilation is crucial for a successful moisture strategy. The new technique of moisture design is done to specifically to reduce the electrical demands required to manage moisture and eliminate the potential growth of mold and mildew in the home.
The envelope consist of the foundation, walls, roof, insulation, windows & doors. We were quite fortunate the envelope system we selected, SprayRock, has ALL of the features we need in order to accomplish our design and energy requirements without additional cost or additional components: airtight envelope (monolithic structure), high insulation factors in wall and roof, continuous exterior insulation and polymer fasteners to eliminate thermal bridging, excellent water, moisture and vapor barriers, balanced insulation in order to keep moisture outside of wall cavity, and radiation barriers to keep radiating heat out of the wall cavity, attic space and living space. The only variation we have incorporated in our home is the use of “moisture and mold resistant” wallboard throughout the whole home as an extra layer of protection while reducing the need for energy. The use of non-moisture absorbing materials is a key component to our “passive moisture” strategy – from the floor to the walls and to the ceiling. Our door and window selection will be based on two factors: low E glass and air tightness. The air tightness being the most important (exterior – interior air exchange creates the greatest load on the mechanical cooling system) because it is the goal of our passive design to have every window shaded from direct sunlight thus reducing the demand for low e windows and the cost that is associated with these high performance windows.
Secondly, we look at all electrical systems we are installing in the home to insure they are the most efficient possible with the capability of provide and using direct current. The air conditioning system (HVAC) consumes the most energy in homes built in warm humid climates. It is crucial to install the most energy efficient unit as possible and one capable of running directly off of Direct Current One that consumes the least amount of energy while running and one that allows for the most control zones as possible. One that is highly efficient managing moisture separate from temperature, and one that is remotely programmable by zone. Kitchen appliances need to evaluated, energy star a min, and the use of. direct current, natural gas and propane where possible is recommended. Laundry room appliances need to be reviewed, energy star a min, and direct current, natural gas and/or propane is recommended for the dryer. Swimming pool pumps need to be evaluated to insure they are the most energy efficient as possible and can be power by direct current. Big screen TV’s need to be min “energy Star” rated. Lighting has become much easier to solve with the drastic drop in the price of LED lights. I feel the rapid drop in prices has been overlooked by many in the industry, business in general and our government. POE – “power over ethernet” (direct current) will be used to connect a smart grid of lighting through out the inside and outside of the home. A great example of capitalism integrated with a government regulation (we all thought it was stupid at the time) was when the government banned the 40 & 60 watt incandescent light bulb in January 2014. Who would have ever thought the 60 w bulb would hit LED parody in just 2.5 years. What I mean is I just bought a 50 watt (close to 60 watts) equivalent LED bulb that uses 5 watts of power, color spectrum of 2700 kelvin, and paid 99 CENTS at IKEA. Prior to the outlawing of the 60 watt bulb, you could not buy one an incandescent bulb for 99 CENTS. We reduced energy CONSUMPTION by 80% at the SAME PRICE POINT. We will be installing LED lights inside and out. The development of a DC micro-grid in place of the current AC utility grid would eliminate the need to convert DC to AC to DC increasing our efficiency and resiliency. Government and utility regulations will be our single largest hurdle to the development of a self sufficient resilient DC Micro-grid.
Thirdly, is the installation of a comprehensive energy management system. The system needs to serve two functions: Tracking and control. Home managements systems need to track the consumption of energy down to every device in the home or at least to a level of a circuit breaker. Only at this level will we be able to control the consumption of our energy. The control will allow us to turn on and off all lighting, some devices and outlets. The tracking and the control needs to be mobile based to insure the ease of management from anywhere at any time.
Now that we have a high performance envelope, with highly energy efficient electrical devices, and connected with a cloud based management system, we are ready for our energy calculation in order to determine how few solar panels we will need. The solarization of the home is the last part and is not done until all of the above has been done regardless if you are building new or retrofitting an existing home. Reduced consumption is the key to energy independence. In addition, to augment our solar production, we will also be adding a 3kw wind generator due to the strong prevailing winds we receive on the eastern side of the hill in Jensen Beach. In regards to personal responsibility, if you only produce a certain number of kilowatts of energy per day, you will quickly learn how to manage your consumption of kilowatt hrs to match your production – otherwise you go DARK.
Affordable energy independent housing is the future to Americans moving out of the urban areas back into the heartland and re-establishing the techno/ clean manufacturing industries that will allow this nation to return to a position where it will compete and maybe even dominate on a global scale. We are very excited to demonstrate for our community and the nation how an integrated energy plan can produce an affordable home that requires no external electricity and or energy.