Sustainable Lake Living

"Ventanas al Cielo" - Windows to Heaven

Radiance Energies Custom Designed:

Photovoltaic (PV) and Solar Domestic Hot Water Systems (SDHW)

One of our goals in designing and building Ventanas al Cielo was to strive for energy independence. The term Zero Net Energy (ZNE) is a home or building with a zero net energy comsumption and a zero carbon emissons annually. Beyond that energy-plus buildings produce a surplus of energy over the year. That energy in the form of electricity is harvested from our home and sent to our utility provider - Jackson EMC through the "grid" for which they compensate us. Compensation is in the form of an initial one-time payment for intstalling PV and SDHW, as well as for generating and selling electricity back to the grid; this offsets power from the grid and is known as parallel generation, or Net Metering.

Photovoltaic (PV) is a method of generating electriccal power by converting solar radiation into direct current (DC) electricity using semiconductors, solar panels and inverters that change the DC electricity to alternating current (AC) - what you more typcially use in your home.  Solar Photovoltaic is a sustainable / renewable energy source. Based on significant research our AFTER TAX RETURN ON THE INCREMENTAL WILL BE NO LESS THAN 12% PER ANNUM (approximately 20% pre-tax) with little to no risk. Actually as time marches on we all can rationally expect that energy costs will go up (they never go down) and therefore our annual return on investment will also increase overtime.

Also consider return on invesment. When the day comes where we have to sell Ventanas al Cielo, the lucky new homeowner will not have any energy related costs, and will in theory be able to afford a higher mortage payment which obviously translates to a HIGHER market value.


Equipment Specifications:

Panel Manufacturers:

Suniva PV panels (260 watts each)

Two AET Flat Plate Solar Hot Water Collectors

PV System:

33 Suniva 260 watt solar panels – 8.58 kW

Siemens Micro-Inverters

Disconnects and monitoring system

Suniva is a US based company spun out from Georgia Tech University of Excellence in Photovoltaic’s (one of only two such research centers in the US). Suniva panels provide one of the highest power outputs per square meter at an affordable cost.

The Siemens Microinverter System improves energy harvest, increases reliability, and dramatically simplifies design, installation and management of solar power systems. Each Suniva solar panel has its own microinverter which can be remotely monitored 24 / 7 on our PC or IPad. Remote monitoring allows you to check on panel production. Having a dedicated inverter for each panel simplifies the processing of identifying broken panels or low panel production.

Summary of energy generation and savings:

Watts per panel                                  260 watts DC

First Year Power Generated                11,583 kWh

Federal ITC                                        10%

State ITC                                           35% up to $10,500

Utility rebate                                      $450 per kW

CO2 Reduction                                   8.6 tons per year

NOX reduction                                    103 pounds per year

SOX reduction                                    24 pounds per year

Cars off the road                                 1.5 cars per year

Water saved                                       6,950 gallons per year

Acres of trees saved                           2.3 acres per year

SDHW Closed Loop – Drainback System:

Two AET 4 foot by 8 foot flat plate solar collectors

80 gallon 316l stainless steel heat exchanger tank

10 gallon 316 stainless steel reservoir


SunEarth LED controller

AET – Alternate Energy Technologies, LLC has provided a 10-gallon stainless steel drainback system, and an 80-gallon DBS Thermomiser storage tank. Heat exchange is provided by high output stainless steel elements. Back-up is provided by electric elements (Ventanas al Cielo has a 7.5 kW Generac Emergency Generator that runs on propane for back-up on the rare occasion that there is an electric “brown-out” and no sun).

SunEarth has been protecting our environment since 1978. Solar Domestic Hot Water (SDHW) system controls allow for 24 / 7 monitoring, data logging, adjusting for seasons, timer and holidays and preventive maintenance (overheating and freezing).