By taking gradual steps to combine power effectivity, photo voltaic and storage, charging for electrical autos, and managing when power is used, our properties can run on clear power and be microcosms of what massive utilities obtain.
Stephen Smith | October 19, 2023
| Clear Vitality Technology, Clear Transportation, Vitality Effectivity, Photo voltaic, Tennessee, Utilities
As a part of the Clear Vitality Technology webinar sequence, SACE is profiling our Govt Director Dr. Stephen A. Smith’s residence. Steve is sharing modifications and upgrades to his Knoxville residence through a webinar on Wednesday, October 25 at 1:30 ET to indicate an instance of a clear power residence.
Video Tour of the Smith Household’s Clear Vitality Dwelling
My household bought our residence in Knoxville in 2006 with a plan to stay right here quickly and finally to construct a brand new residence from scratch to make the most of clear inexperienced expertise as a lot as attainable. In 2008, we switched gears – we determined that the higher method was to enhance the present residence. This has been a multi-step course of with a number of planning and forethought with a purpose to hold it inside our price range and use sensible sequencing. At present we’re very pleased with the place we stand, and we proceed to be happy with the efficiency of the entire additions and modifications.
I additionally need to acknowledge that we’re lucky to have some sources that others could not. This is the reason we’re breaking down the steps and items to indicate there are issues individuals can do inside any price range. These steps may be constructed upon, particularly now with incentives and rebates from the Inflation Discount Act (IRA).
Moreover, there are at all times questions on whether or not these are sensible investments that deliver worth to the house owner. All of us have various things we worth greater than others. I can say with certainty that I’ve by no means regretted any of our investments outlined right here. Our house is extra snug, more healthy, and smarter, and permits us to really feel we’re a part of the Clear Vitality Technology working for options. Moreover, there may be clear proof that many of those investments not solely pay again with month-to-month dividends from financial savings but in addition enhance the general worth of your house if and when you could promote it. Would I’ve put photo voltaic panels on a home that I used to be not going to stay in for greater than 5 years? Possibly not. However as we watch the ravages of local weather disruption, the underside line for my household has been that our residence isn’t solely extra resilient, additionally it is an try to mannequin a brand new future that works with utilities to search out options. From a values perspective, that is priceless.
Begin with Vitality Effectivity to Stretch Each Electron
We started the improve course of deliberately, spending time planning and making a logical plan of action. The pure place to begin was to put in in depth power effectivity enhancements: first tightening up the house by decreasing air leaks, altering to environment friendly lighting, changing the home windows and insulation, and switching to electrical home equipment.
Effectivity is the muse {that a} clear house is constructed upon – a house that stretches each electron so far as attainable makes the very best use of power, whether or not it depends on conventional utility-generated energy or 
sexier elements like photo voltaic and storage. Air sealing, lighting, home windows, and insulation are first to return to thoughts when contemplating effectivity upgrades. The subsequent lowest hanging fruits are HVAC and electrical kitchen home equipment, so we added a geothermal warmth pump and induction cooktop within the kitchen.
Past these extra apparent effectivity enhancements, we added 9 Solatube photo voltaic tubes to our inside areas. These intelligent lighting alternate options deliver pure daylight into inside rooms, decreasing lighting wants, AND can operate as conventional lighting fixtures at evening. The Schüco photo voltaic sizzling water heater we added is one other effectivity achieve: water is pre-heated earlier than it goes into the electrical sizzling water heater, so somewhat than beginning with 50-60 diploma water, the system begins with 100+ diploma water, relying on the season, which means {the electrical} factor within the sizzling water heater doesn’t need to run as a lot for us to have prepared sizzling water.
1st Section Photo voltaic: Grid-Tied
As soon as we established an energy-efficient basis, we have been prepared for our first photo voltaic photovoltaic (PV) set up: a 7.13 kW Sharp rooftop system comprised of thirty-six 198-Watt photo voltaic modules put in by GES Photo voltaic. On the time,
Sharp was making these panels in Memphis TN. This method just about offset the overwhelming majority of our family power use, particularly throughout spring and fall when solar is plentiful and HVAC wants are much less.
At the moment (2009-2010), TVA was successfully operating a photo voltaic buy-back program that we have been eligible to make the most of referred to as Technology Companions Program, which is principally like a feed-in-tariff (FIT) program the place the house owner is sure to promote all electrical energy produced to the utility, 
and the utility is sure to purchase it. Technology Companions required a 20-year contract: for the primary 10 years TVA paid us a premium or 12 cents above retail (~21-22 cents/kwh); now that we’re within the second 10 years, TVA pays us the retail price. When the solar shines, the 7.13 kW system generates electrical energy, measured with a devoted meter. A separate meter is a conventional meter measuring how a lot energy is getting used/pulled from the grid. This system has been discontinued, however the 7.13 kW system at my residence stays ‘grandfathered in’ for about six extra years, which means that this technique stays contractually grid-tied, offsetting the price of any electrical energy we pull from the grid first, after which producing earnings with no matter we generate above that.
2nd Section Photo voltaic: “Behind the Meter”
With my household increasing in 2019-2020, we put an addition on the house, which created further south-facing roof area for extra photo voltaic panels. This method is smaller – 3.96 kW – and is “behind the meter.” Energy from this 3.96 kW system, which is comprised of twelve 330-Watt REC photo voltaic modules and put in by Lightwave Photo voltaic, meets family load first. Whereas the unique panels stay interconnected with the grid, these new panels run straight to 2 13.5 kWh Tesla powerwalls (additionally put in by Lightwave) – giving us a complete of 27 kWh of storage at our residence. If powerwalls replenish, we will plug in certainly one of our electrical vehicles and take all the additional energy.
Including Storage Helps Transfer Us Towards Web-Zero
These compact powerwalls actually are one of many keys to creating the system self-sufficient. If the three.96 kW system supplies sufficient for our residence wants at a given time, we’re net-zero – requiring no power from the grid in any respect. If we’d like lower than the panels generate, the excess runs to the powerwalls and may be saved for future use.
This clearly saves us cash; it additionally saves us fear and inconvenience throughout outages. Take into consideration this: a ‘typical’ American family makes use of ~1000 kWh of electrical energy monthly. That is (very) roughly averaged at round 30 kWh/day. The 2 powerwalls whole 27 kW, so if TVA loses energy, and my powerwalls are full, I can energy the home for a few day with out being replenished with sunshine. If the solar is out, there’s no restrict to how lengthy we might run the home usually with out grid energy. Since we put in the brand new system and the powerwalls, energy has gone out in our space at the very least 5 occasions, largely for brief durations of minutes. However a few notable occasions, our a part of Knoxville has been with out energy longer, at the very least as soon as for a lot of hours. We have now but to be with out energy since putting in the storage system.
Time of Use: Mutually Helpful Incentives for Owners & Utilities
We are actually a part of a pilot program with Knoxville Utilities Board (or KUB – our native supplier, which purchases energy from TVA and sells to Knoxville clients). By way of the pilot, KUB is making an attempt to make use of “time of use” incentives to handle demand. Underneath this pilot, KUB institutes “peak” service occasions to correspond with the time it prices them (KUB) extra to purchase electrical energy
from TVA – they cost residential clients considerably extra for power used throughout “on peak” occasions, and fewer for power used throughout “off-peak” every day. On peak in winter is 5 am-11 am, and in summer time 2 pm-8 pm. Clients who decide in to this program buy electrical energy used in the course of the 18 off-peak hours of every day at 2 cents beneath customary price. To incentivize clients to actually roll again power use throughout peak hours, KUB then expenses nearly twice the usual price (21 cents or so) throughout peak hours. My family has been taking part for a little bit over a 12 months and we now have saved about $400.
Time of use additionally advantages the utility immensely: Huge central station vegetation are notoriously rigid and are continuously responding to the power a great deal of trade, companies, and householders. Peak load is totally different in numerous geographies, particularly when utilities usually cowl widespread areas. These peaks and valleys make it costlier and fewer environment friendly to offer dependable energy, and utilities use “peakers” – steadily fossil gasoline vegetation, that they need to activate and off to satisfy fluctuating demand. Using sensible expertise to control demand occasions (say, by charging an electrical automotive in a single day or utilizing self-generated photo voltaic power throughout excessive peak occasions) flattens the load curve, making the complete system extra environment friendly. An built-in residence that has its personal potential to generate energy and retailer energy can – with time of use charges – grow to be a useful participant within the utility’s load points.
The Evolving Function of the Electrical Automotive
Once we leased our first electrical automotive, a Nissan LEAF, we had solely our grid-tied 7.13 kW rooftop system, and charging the automotive at house is primarily what drove our consumption out of the vary of internet zero, making it a problem for our try to take care of a internet zero residence. At present, we now have two Teslas in my family, every with a 75 kWh battery. These two vehicles can retailer 150 kWh, nearly 6x the storage of my two Tesla powerwalls, with none further upfront expense or want for cupboard space (you’ll have a automotive, proper?). On the ‘typical’ family demand of ~1000 kWh of electrical energy monthly or ~30 kWh / day, a automotive with a 75 kWh battery might energy your house for 2 days. As expertise advances and we transfer towards sensible properties and autos with two-way energy integration, electrical vehicles will probably be an vital element of a carbon-free way of life.
Photo voltaic + Storage: An Efficient Answer on the Micro & Macro Degree
I like to think about all of those elements as more and more built-in – my residence, storage, electrical automotive, and photo voltaic panels are a part of a single system giving me, the house owner, most flexibility in managing my very own reliability, environmental attributes, and, particularly with time-of-use in place, my utility invoice. Principally, this provides me the capability to regulate my very own power future.
Photo voltaic + storage works on a micro degree at my residence. It will probably work on a macro degree as effectively. I’ve mentioned many occasions that I actually imagine it’s a crime to burn fossil fuels in the course of the daytime when the solar shines on us. Now, with storage applied sciences and infrastructure rising so quickly, extra may be captured and dispatched at evening or at peak occasions on the utility degree as effectively.
Abstract: Every Particular person Step is A part of the Collective Answer
As a part of the Clear Vitality Technology, we’re all searching for methods to be a part of the answer as an alternative of a part of the issue. However you don’t need to do every thing that this home has integrated – keep in mind, we did every thing step-by-step, not suddenly. This weblog and video are simply alternatives to see how clear power residence applied sciences combine. You may take every particular person step as a part of the answer, and people steps actually matter – particularly with power effectivity, as a result of the greenest electron is the electron we by no means use. Now that we’re beginning to have entry to extra photo voltaic expertise, electrical autos, storage, and sensible meters, and utilities are beginning to supply time of use charges, all of it integrates in order that we will grow to be a part of the answer in a complete, collective means. Take it step-by-step. Do the issues that make sense which you could afford, beginning with power effectivity.
Watch the video in full right here, or watch some older movies highlighting totally different elements right here:
The Clear Vitality Technology is Embracing the Challenges & Alternatives of Our Time
Our era stands at a defining fork within the highway ahead. The popular path is what we’re calling the “Clear Vitality Technology.” As members of the Clear Vitality Technology, we acknowledge the second we’re in by selecting motion over despair. This Clear Vitality Technology embraces each the challenges and alternatives of our time. And as plentiful the challenges are in right now’s world, the alternatives are simply as many, and rising by the day. Expertise is growing at an exponentially speedy tempo, and favorable insurance policies that encourage and favor adoption and progress of fresh power sources have a multiplier impact.
It’s our generational problem to confront local weather disruption collectively, coming collectively to reply to the best problem of our time.
By supporting favorable insurance policies, and on the similar time embracing the methods we will – as people and collectively – be part of the motion, we’ll assist pace the transition and produce it to the dimensions on the timeline we so desperately want. Our properties can generate energy when the solar is out and reduce demand on utilities to assist hold our payments down, and on the similar time assist utilities decrease their prices and demand on their tools. Expertise is offered – right now – to make our properties extra environment friendly and dependable whereas transferring away from our want for fossil fuels fully. And with insurance policies driving costs down and applied sciences turning into extra broadly accessible, our properties may be microcosms of what our bigger utility-based electrical system must grow to be.
Photo voltaic + storage, if scaled correctly to the utility degree, can offset the necessity for fossil fuels.
To create thriving communities, we should acknowledge the urgency of the second and take decisive motion collectively now. The Clear Vitality Technology is selecting motion over despair and gaining traction towards a more healthy and extra sustainable, pleasant world than we’ve dared to think about.
Make Your Subsequent Step Your First Step
Do the issues you may afford and really feel good to you. Vitality effectivity is crucial first step in upgrading any residence, and effectivity enhancements are available all sizes and shapes and value tags. Bear in mind: “The greenest electron is the one we by no means use.”
Subsequent, discover out what your utility and state supply: does your utility supply time-of-use pricing? Is it higher to promote again generated energy or hold it at residence? In lots of our Southeastern states, sadly, utilities aren’t paying a very good price for energy from rooftop residential methods, which means that oftentimes photo voltaic+storage might be the best choice for householders right here.
It begins with small steps – asking questions and becoming a member of collectively as neighbors, college students, and buddies to determine which particular local weather actions may gain advantage our communities. A simple, accessible first step is to affix the Clear Vitality Technology for our upcoming webinar on Oct. 25 at 1:30 PM ET:
