Rooftop Evolution: The Convergence of Roofing and Energy Technologies, Taking A Look At the Possibilities & Contingent Liabilities
Original article published by Building Management Hawaii (Feb/Mar 2012 Issue) view the full article here.
ROOFTOP EVOLUTION: THE CONVERGENCE OF ROOFING & ENERGY TECHNOLOGIES
Taking a look at the possibilities and contingent liabilities.
By Guy Akasaki, Commercial Roofing & Waterproofing Hawaii, Inc.
The convergence of “known” technologies and “new” technologies always exposes a gap in the process of developing a working model for the ideal integration of the two. In most cases, the individual components of a system do not fail – it’s the integration point that is often the weak link. With PV going strong in Hawaii, the successful strategy of waving the bright shiny object of tax credits for PV lures us in but many still are unsure on how to best capitalize on it and more importantly – how to incorporate a full turnkey solution at the front-end built to stand after the credits are captured and accelerated depreciation is claimed. Make an informed decision that captures savings alongside long-term sustainability by taking a holistic approach to integrating sustainable building applications.
There are an array of roof top solutions that will deliver the most benefit to your building by addressing all related facets – possible energy savings, financial feasibility, existing roof condition, and hedging against potential litigation related to roof integrated energy solutions. Whether you are a building owner/investor or a property manager/AOAO board member – below are some industry best practice considerations to keep in mind as you navigate towards implementing energy efficient solutions from the rooftop that work best for you. Your roof is critical to the operation of your building, and any interruption to that operation can be disastrous.
No Two Roofs Are Alike.
Not every building may be a best candidate to host a rooftop photovoltaic system. However, there are other roofing integrated solutions available to help minimize the overall operating costs such as cool roofs, solar reflective shingles, BIPV and solar shingles, day-lighting, attic insulation, roof vents and attic fans to name a few. Cool roofs can reduce the temperature at the surface of the roof from +/- 170 degrees to ambient in many cases and could reflect in a temperature difference at the ceiling inside of 10 to 15 degrees. Again, the formulation of the cool roof coating is incredibly important to long-term performance. In an air-conditioned space the potential savings through energy efficient applications can be substantial. Consider a cool roofing assembly combined with fiberglass R-20 insulation batt over the roof rafter that could add another 10-20% reduction in heat radiation. With the advent of nanotechnology, UV and infrared particulates have been incorporated in asphalt shingles and color pigments offering a capability of generating 35% plus solar reflectivity. These are a few of the energy efficient approaches available for the rooftop.
What are my options to lower the energy costs of my building from the rooftop?
Take a look at your building from the top down to get a good idea of what options you have to reduce energy demands. Selecting the best roofing system for the type of business operating below it is huge! A cold storage warehouse is going to have a different energy demand from that of an observational facility that prefers natural sunlight. A single-family home in a community association will have a different energy demand from that of a 50-story condominium. Matching the optimal roofing system to the function within the building is key to maximizing an investment in a new roofing system.
If I am looking into installing a rooftop photovoltaic system for my building – what should I be aware of regarding the existing roof?
Special care is needed in the design, manufacture and installation of the roof assembly and the integration of the roof-mounted PV system to ensure all components work together to create a roof assembly that not only produces electricity but also is weatherproof and reliable. Keep in mind, components generally don’t fail – but it is the systems integration of components in the assemblies that fail. Lack of attention to details can result in big leaks and big headaches later. General considerations that the NRCA has pin-pointed include load (which generally requires a professional structural engineer), drainage, affect on the rate of aging of the roof, roof surface temperatures, rooftop traffic, site orientation (shade), warranties and equivalent service life. Also important is making sure that the manufacturer’s requirements for the roofing system are met so that the warranty is not voided. A typical PV installation can include anywhere from dozens to hundreds of penetrations to the roofing system – every penetration requires a specific type of flashing to ensure a sound waterproof platform for a power generating array. Keep in mind that there are many roofing types of various formulations and nomenclatures. Materials compatibility are concerns for high consideration due to the advent of technology which has increased performance life expectancies. One cannot under emphasize the continuity of the manufacturer warranty, which is in many cases worded to protect the manufacturer of the roofing assembly. As a side comment, there are an elite amount of roofing manufacturers which will support a systems warranty if property disclosure and pre-job information is provided in compatibility with PV systems. Keep in mind, when a system NDL warranty is acquired – the customer is backed by manufacturers with strong financials to be able to weather the ups and downs of the economy to support the warranty.
How does investing in clean energy actually pay back?
Commercial development of renewable energy and energy efficiency is critical to Hawaii’s energy future. Building owners can hedge themselves against rising energy costs and can provide additional streams of income to their bottom line. From a holistic perspective, the valuation of real estate as an income-producing asset is determined by the income it generates. What is the one floor on any building that generates no income? It’s the roof. By installing a photovoltaic system on a building’s roof, it now becomes a distributed energy generating facility that is now capable of generating additional income – which was not possible before the array was installed. What does an additional stream of income do to the asset? It raises the valuation of the asset.
As an example, given the net present value of money in regards to fair market values (FMV), one might consider that with many oil sources half peaking which represents a higher cost of oil and the price of oil rising not only because of demand, it will make the distributed energy generating facility a very important component of real estate especially if it is a sizable array. Imagine what the present value of the energy sold to tenants 20 years hence?
If an AOAO is considering PV for their buildings, what should they be aware of?
If an AOAO wants to use PV to reduce their overall energy consumption, they need to consider that the common area of the roof needs to be bifurcated equally to all owners. The installation guidelines for PV in accordance with the common area roofing installation should be executed so as not to void the warranty. The association may want to consider limiting PV installers or developing a standard for installation guidelines to allow for consistency in common area elements. So as one can see, it needs to be a well thought out plan.
At the end of the day, what you don’t want is a cheap poorly executed excuse of a roof that will probably cost you more in long-term repairs and/or re-roof prematurely. What you do want is a fully integrated roofing assembly (capable of being integrated with PV if intended) that delivers a cost-effective, energy-efficient solution with a maximum return on investment. Imagine how seamless it would be to have everything dovetailed into one warranty with one point of accountability. You don’t have to look to far – you just have to look carefully. While few and far between, there are indeed a few contractors that can deliver a fully turnkey solution. Remember, in most cases the individual components typically don’t fail. It is the systems integration to perform over the long haul that causes the ruckus.
Guy Akasaki is President & CEO of Commercial Roofing & Waterproofing Hawaii, Inc., a full-service roofing and waterproofing contractor a.k.a. “crook, liar & thief.”
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