Building Energy Resilience

A recent blog post in Energy Manager Today highlights the increasing demand for, and utilization of, building energy management systems. The market for building energy management systems (BEMS) is expected to more than triple in size in less than 10 years. Furthermore, the use of BEMS may expand to include the significant energy consumption of transportation access to/from buildings (a topic I have blogged about previously). A BEMS can enable effective energy management if it provides the right information to the right people at the right time.

On a recent project we were tasked with trying to reduce the peak electric demand of a building that already had a relatively low summer peak demand of around 40-45 kW and even lower winter demand of around 25 kW.  Immediately ideas jumped into our head that we should look at the four installed rooftop units and the commercial kitchen equipment as sources for peak electric demand savings.

Meter First

Before we began any analysis though, we metered the feed of nearly every electrical distribution panel in the building to check for any anomalies.  We found what was expected – the kitchen and RTUs accounted for a large amount of the electrical demand.   However, when we compared this data with the utility meter (total power of the building) data for the same time period we found that one feed we did not meter turned out to be an important one.

Over the past six months, I have been taking on a new role at Cx Associates as an owner’s Project Manager for a large organization in Burlington, VT. This has given me the opportunity to be part of a construction team - not as part of the commissioning firm, but rather by working for the owner in overseeing the project in its entirety. One of my current active projects is an HVAC mechanical upgrade in an office building known for occupant comfort issues. In this post, I will describe one of the difficulties we needed to overcome with this particular project, as well as a helpful tool that has been very useful for me as a Project Manager.

In the mid-2000s, the late US Senator Ted Stevens (R-Alaska) famously used an analogy for the internet as a series of tubes. The full analogy was a bad one, and was concerning since it revealed to the tech savvy public how little the congressional entities in charge of creating policy actually understood the technology to which they were attempting to tailor policy. Incidentally, the needle has not moved much in this area in the intervening decade (crypto back-door arguments being a prime example), but that is a blog post for another time.

Retrocommissioning (RCx) or Existing Building Commissioning refer to a technical process that retrofits and tunes building HVAC control systems so that buildings function more efficiently and effectively.  The RCx process has historically included three primary phases:

During the Kyoto Protocol meetings, the world thought governments were going to lead the carbon-emission reduction efforts. But the foremost carbon-emitting countries (US included) didn’t sign this protocol and, until recently, seemed content with sidestepping any commitments.  Now 25 years later, the world itself is calling for change, and governments are finding grassroots support from the public as they go into the Paris Climate Change discussions.  Companies world-wide are initiating energy and waste reducing measures and promoting renewable energy procurement themselves, without mandates, because they see the economic benefits.  The tide has turned.

I’ve noticed a common problem across a range of buildings due to the idea that all PID controls behave the same.  The result of this misconception rears its ugly head in poor tuning and poor implementation of PIDs that can cause your HVAC system to perform poorly for years.  The PID is a great means to realize your design intent, if you know how to properly spell out for your controls contractor what it is you’re looking for.   But before that, let’s get the basics down first - What is a PID?

Energy efficiency upgrades are widely recognized by facility managers as good investments with the potential for short payback periods and attractive lifecycle costs. However, energy efficiency investments are also often viewed as an added expenditure in competition with capital investments in infrastructure driven by end users and/or the mission.  Some managers may fear a tradeoff between energy efficiency investments and other improvements in building performance, such as better indoor environmental quality (IEQ) or lower maintenance costs. In my view, the tradeoff between energy efficiency investments and other improvements in building performance is a false dichotomy - energy efficiency investment opportunities can reduce costs while enhancing building performance to better satisfy end users and the mission. 

Variable Refrigerant Flow (VRF) systems are becoming an increasingly popular HVAC solution for commercial construction projects around the country.  They offer many benefits that can be realized by architects, engineers, contractors, and end users. Some of the benefits include energy efficiency, flexible installation, and local controls for end users. I began my career by spending two years as sales rep for a VRF manufacturer, and the following are some observations I made during that time about issues which commonly caused problems during installation.

In the five years or so between the late 2000s and 2014, prices for large-scale solar photovoltaic (aka “solar PV” or “PV”) power generation installations have fallen by 50% due to reasons including incremental technology improvements, higher production volumes, more efficient manufacturing, and more efficient and competitive installation. The news of falling large scale solar PV costs is not new to those who follow these kinds of things, but the continued drastic decline in prices has brought us to a point worth noting. A recently released Lawrence Berkeley National Laboratory (LBNL) report on this subject titled Utility-Scale Solar 2014[1], found that the 20^th percentile of utility scale PV project costs (the least-expensive 20%) were installed for around $2 per Watt_AC. Some notable recent utility-scale PV power purchase agreements (a.k.a “PPAs”, which are contracts between producers and buyers of power typically for a fixed price per megawatt) in the Southwestern US have been for prices as low as $40/MWh—the study notes that at this price, solar PV is competitive with the fuel-only component of operating a natural gas plant (i.e., ignoring gas generation fixed capital costs such as the power plant itself!).