A great way for editors to track reader preferences is to research which products received the most requests for information via the “circle numbers” found at the end of product mentions in our print editions. Before getting my hands on the response list for 2008, I had assumed I’d see some innovative items at the top and that maybe it would reveal some interesting trends.

What I found was total solar domination. Every item in the Top 10 was a photovoltaic product, eight of them from our Summer issue article on solar power. A PV product also claimed the No. 12 spot and solar hot water heaters filled the No. 11 and No. 13 spots.

The trend ended there, however, as the remainder of the Top 20 included a range of product types, from water collection to balcony decking.

In case you missed them the first time around, here are the Top 20 products EcoHome readers wanted to know more about in 2008:

#1 Ready Solar: Solar in a Box (from Winter 2008 issue)
A prefab, modular solar electric system with frame mounting, Solar in a Box is sold off the shelf for an alternative to more expensive, custom photovoltaic systems. It comes with all components for easy installation with no adjustments needed, the company says, and includes Web-based monitoring. The pre-assembled system can be customized and is compatible with any roof surface. 877.817.3239. www.readysolar.com.

#2 Akeena Solar: Andalay Solar Panels
Andalay solar panels feature built-in racking and built-in wiring for a smooth, flush appearance that resembles skylights. With 70% fewer parts and 25% fewer attachment points, the panels for a small house can be installed in less than an hour, the company says. Fewer attachment points also means fewer penetrations in the roof, so less opportunity for leaks and failure. 408.395.7774. www.andalay.net.

#3 Ready Solar: Solar in a Box (from Summer 2008 issue)
The Solar in a Box system is a factory-assembled, 2-kW standardized solution for residential applications. Each racking system accommodates a PV module measuring 10 by 6 feet to deliver 0.5 kWh of electricity. The turnkey solution (including modules from one of several manufacturers) consists of panels, an inverter, mounting system and hardware, and roof jacks and flashing. The homeowner can monitor the system’s performance online, and battery backup is available as an optional upgrade. 877.817.3239. www.readysolar.com.

#4 EcoTechnologies: PVL-FlexLight PV Panel
PVL-136 FlexLight is a flexible, lightweight, laminate PV panel that adheres directly to the roof finish without nullifying the roof’s warranty. The panel’s laminated design captures the complete solar spectrum more efficiently than traditional systems, says the manufacturer, to produce more electricity per watt; the top layer minimizes power loss when the panel is shaded. Each panel measures 216 by 15 1/2 inches, achieves an STC maximum power rating of 136 W, and is code-approved for use in Miami-Dade County, Fla. 888.522.3626. www.ecotechnousa.com.

#5 Sanyo: HIT Series PV Panels
HIT Series photovoltaic panels for residential, grid-connected systems feature a proprietary hybrid of single crystalline silicon surrounded by ultra-thin, amorphous silicon layers to reach greater cell and module efficiencies. Panels measure 51.2 by 35.2 inches, achieve an STC maximum power rating of 180 to 205 W, and boast conversion efficiencies up to 17.4%. Bifacial models also generate electricity from ambient light that has passed through the panel or is reflected off surrounding surfaces. 469.362.5645. www.us.sanyo.com/solar.

#6 Kyocera Solar: KD Series Solar Modules
A trio of KD Series solar modules uses a larger and more powerful solar cell to deliver a higher output per module and achieve an STC maximum power rating of 135 to 205 W, depending on the model, says the firm. The MyGen Grid-tie Photovoltaic Power System offers a complete package of modules, inverter, wire and lightning protection, and mounting and mechanical support that hastens installation and meets most code and utility requirements. 800.223.9580. www.kyocerasolar.com.

#7 Evergreen Solar: ES-Series Polycrystalline Solar Panels
ES-Series poly-crystalline solar panels feature String Ribbon wafer technology. The panel’s design consists of 108 poly-crystalline silicon solar cells, anti-reflective tempered solar glass, EVA encapsulant, polymer backskin, and a double-walled anodized aluminum frame. Each panel measures 371/2 by 61.8 inches and weighs 40.1 pounds. Three panel options achieve an STC maximum power rating of 180 to 195 W; multiple mounting options enable installation versatility. 508.357.2221. www.evergreensolar.com.

#8 Luma Resources Roof Mounted Solar Kit
This residential roof-mounted solar kit, invented by a roofing contractor, uses thin-film PV technology and consists of 60 solar shingles, a DC-AC inverter, and all flashing and fastening components. Each interlocking shingle measures 51.125 by 15.625 inches and achieves an STC maximum power rating of 31 W. The system is designed to integrate with common horizontal roof shingle layouts. 888.733.5862. www.lumaresources.com

#9 Sharp Electronics OnEnergy System
Poly-crystalline modules feature a textured solar cell surface that increases light absorption and improves efficiency, while a bypass diode minimizes the power drops under shady conditions. The module achieves an STC maximum power rating of 187 W and a 12.7% conversion efficiency, and is designed for the company’s solar racking system. Sharp’s OnEnergy system offers custom designs and delivers a complete package of all components and fasteners. 800.765.2706. www.sharpusa.com/solar.

#10 Sunpower Corp.: Sun Tile Roof Tiles
SunTile roof tiles and solar panels provide a built-in look for various roof finishes. The tile product suits S-shape and flat tile profiles; each panel measures 17 by 59 inches and achieves an STC power rating of 63 W. Panel-designed products integrate with various roof finishes, measuring 61.39 by 31.42 inches and achieving an STC maximum power rating of 210 W and a conversion efficiency of 16.9% per panel. The company’s solar cell technology delivers up to 50% more power than conventional cells and converts up to 22% of available sunlight into electricity. Both systems are available with optional online monitoring service. 877.787.6527. www.sunpowercorp.com.

#11 Sunda: Solar Hot Water Tubes  www.sundasolar.com

#12 Global Solar: PowerFlex Solar Strings
Global Solar. PowerFlex Solar Strings offer a pre-connected format for the company’s flexible Copper Indium Gallium diSelenide (CIGS) cells, allowing manufacturers of solar products and modules (i.e., the end products installed on houses) to more easily fit thin-film cells into their manufacturing processes. The CIGS cells are made on a bendable substrate, the company explains, making it more adaptable in shape and size and thereby allowing for new and innovative designs. 520.546.6313. www.globalsolar.com.

#13 Heat Transfer Products: Phoenix Solar Water Heater
The Phoenix solar water heater combines domestic hot-water storage with a 97% efficient, gas-fired backup in one unit. In addition, the unit features side tappings in the jacket that permit auxiliary connections to a hydro-air system for space heating. Made from stainless steel, the product incorporates a dedicated solar heat exchanger. 800.323.9651. www.htproducts.com.

#14 BaySystems: Bayseal Insulating Foam
A new formulation eases application of Bayseal 1/2-pound spray polyurethane insulating foam, the maker says. It blows with water instead of fluorocarbon- or cyclopentane-based agents, making it more environmentally friendly. 800.221.3626. www.bsna.com.

#15 Rainwell: Underground Cistern
A 1,700-gallon, underground cistern collects rainwater from the roof and disperses it into the garden by way of an irrigation system that automatically taps into city water for backup. 817.676.4440. www.therainwell.com.

#16 Icestone: Recycled Glass Surfaces
IceStone surfaces are made with 100% recycled glass in a cement matrix. According to the firm, the product is the first and only durable surface to receive McDonough Braungart Design Chemistry’s Cradle to Cradle certification. Suitable for a range of indoor and outdoor uses, IceStone is strong and resists heat and scratches, the company says. Twenty-seven standard colors are available. 718.624.4900. www.icestone.biz.

#17 Stiebel Eltron: Tempra Tankless Water Heater
Heating water as it flows through, the Tempra tankless, on-demand electric water heater eliminates the stand-by heat losses associated with tank systems and reduces water heating bills by 15% to 20%, says the firm. The compact unit’s microprocessor control allows exact temperature setting through a knob and a digital display. The heater has all copper piping and heating elements. 800.582.8423. www.stiebel-eltron-usa.com.

#18 Life Deck: Balcony Decking
The outdoor balcony decking is made of a Life Deck system called ALX by Westcoat, a multilayer, self-draining system that’s designed to be super-durable and waterproof. 800.541.3310. www.lifedeck.com.

#19 Huvco: Parans Fiber Optic Skylight
A new way to bring natural light into interior spaces, Huvco’s Parans Fiber Optic Skylight system collects sunlight through lenses on outdoor panels (shown), then funnels the light through optical cables to luminaires. The system’s daylight collectors mount on roofs or façades. The thin, flexible optical cables, which are routed through walls and ceilings, have high light transmission that lets sunlight efficiently reach far into buildings; the luminaires are designed to recreate the feeling of sunlight. Hybrid luminaires that combine natural light and electric light are available. 800.832.6116. www.huvco.com.

#20 Kohler: San Raphael Pressure Lite Toilet
The industry’s first one-piece, 1.0-gpf, high-efficiency toilet with pressure assist technology, the San Raphael Pressure Lite uses compressed air to propel water for strong flushing power. According to the firm, the toilet, which carries the EPA WaterSense label, can save a household of four 7,000 to 10,000 gallons of water a year versus a standard 1.6-gpf model. The unit has Comfort Height seating and an elongated bowl. 800.456.4537. www.kohler.com.