HomeMy WebLinkAboutCC e - Electrical Design Technical Memo
MEMORANDUM
Date: October 4, 2019
TO: Project File
FROM: Richard Burde, PE, Engineer III
Chris Read, Sustainability Manager
CC:
Project Team
VIA: Matt Horn, PE, City Engineer
Brian Nelson PE, Supervising Civil Engineer
SUBJECT: Electrical Design Recommendations for Palm - Nipomo Garage
Introduction
For the last several years the City has aspired to develop the existing surface lot at the corner of
Palm and Nipomo into a multi-level parking structure. Design of the structure began in March
2019 and is currently underway by the project design consultant, Watry Design, Inc. Construction
is expected to start by the end of 2020. In addition to adding much needed parking to the downtown
core, this development provides a valuable opportunity for the City to gain experience in
implementing green technologies in a major capital project while balancing the monetary costs
associated with such advancements.
The Palm–Nipomo Parking Structure is scheduled to go to City Council for approval on November
5, 2019. With the project currently in the preliminary design stage, City Administration staff asked
Public Works staff to investigate and make recommendations on the appropriate level of
implementation of green technologies, including solar and electrical vehicle charging.
This document provides a discussion of the benefits and challenges of such a project and provides
recommendations for prudent levels of green technology implementation in the design of the
structure’s electrical system.
Background
As stated in the City’s Climate Action Plan, San Luis Obispo has set a goal for becoming carbon
neutral by 2035. If this ambitious milestone is to be achieved all viable opportunities for
implementing green technology must be taken advantage of. However, mass implementation of
many emerging green technologies is often cost prohibitive and the City’s desire to show
leadership in environmental sustainability must always be balanced by the monetary costs
associated with these advancements.
The new parking structure at Palm and Nipomo will require a heavy investment from the City and
is expected to have a life span of 50 years or more. This makes it critical for City staff to thoroughly
consider current technologies and consumer trends in parking, as well as try to anticipate how
emerging technologies might affect the future use of parking structures.
Palm-Nipomo Proposal (Preliminary Implementation of Green Technologies)
To date, Watry Design Inc. has produced a preliminary layout of the garage which includes 403
stalls on five levels. Of the 403 total stalls, 43 have been equipped with electric vehicle (EV)
charging stations, or roughly 10% of total stalls. This allocation of EV stalls is in line with the
current City Zoning Regulations see section 17.72.040 which requires 10% of stalls to be EV ready
and an additional 25% of stalls to be made EV capable.
In addition to EV charging, Watry’s preliminary layout includes photovoltaic (PV) panels on the
structure’s top level with coverage equaling 8,935 of the 32,000 total square feet. Photovoltaic
panels would be used to offset the energy demands of the garage, including load requirements of
EV charging stations, as well as reduce the City’s overall dependence on traditional power sources.
Any excess power produced would be directed to the grid, making clean energy available for use
elsewhere.
Green Technologies Currently Available
Upon receiving Watry’s preliminary design, City staff researched whether expanding the use of
green technologies in the Palm–Nipomo structure would be practical. The following section
outlines the current capabilities, limitations, and costs associated with EV chargers and PV panels.
In addition, the potential use of battery walls to offset peak demand electrical pricing will be
explored.
EV Charging – There are now over a million electric vehicles on the road across the US and a
million more are expected within the next three years. California leads the U.S. in EV purchases
where 7.1% of new cars sold in the state are electric. This trend in increased electric vehicle use
presents an opportunity for parking garage operators to attract customers by providing charging
stations in their structures.
Currently there are three primary options available for charging electric vehicles:
• Level 1 chargers - generally installed at private residences, they operate on a 120 Volts
Alternating Current (AC) and require 8-12 hours to fully charge an electric battery.
• Level 2 chargers - the most common type of chargers, these operate on a 240 Volts AC
plug and require 4-6 hours to fully charge an electric battery. Level 2 chargers are
compatible with all electric and hybrid vehicles.
• Level 3 chargers - known as direct current (DC) Fast Chargers, they operate on a 480 Volts
DC and can provide an 80% charge in as little as 30 minutes.
All 43 EV-ready stalls currently being proposed in the Palm–Nipomo structure are Level 2
chargers, each of which will demand 6.656 kilowatts of electricity while in use.
Operating Costs of EV Charging
In April of 2019, the City installed 19 EV Level 2 charging stations in the Marsh St. parking
garage, making it the City’s first significant implementation of EV charging. Despite the growing
popularity of electric vehicles in California and the strong occupancy rates of the general stalls at
Marsh St., use of the charging stations remains low. This is true even though the City only collects
its typical parking rates and does not pass along electrical fees associated with charging to the
consumer.
Analysis by the Parking Services Programs has determined that the average price for power used
in the Marsh St. garage is $0.36 per kilowatt hour, with peak rates of $0.58 per kilowatt hour.
Therefore, a car parked and charging during peak rates incurs an energy cost to the City of
$3.86/hour while only paying $1.50/hr in parking fees.
At this rate, a customer fully charging a vehicle during a 6-hour stay would pay $7.50 in parking
fees ($1.50/hour with the first hour free). During this time the City would incur $23.16 in electrical
costs during peak times which equates to a $15.66 loss to provide this service ($7.50 of parking
fees minus $23.16 electrical cost). During average rate times, the cost of electricity is lower but
still equates to a $6.90 loss to provide this service.
Providing EV charging stalls also brings hidden or “soft” costs to the project by reducing the
parking structures revenue potential. Due to the enlarged space requirements of the EV charging
stations and the need to maintain ADA-compliant paths of travel, the addition of EV charging
stations beyond the 10% base requirement will require the elimination of traditional stalls, further
impacting the structures potential for generating revenue. For example, making the parking
structure 100% EV capable would reduce the total stall count by 35 stalls, roughly 8.6%. With
debt financing being pursued for construction funding any potential impact on the structures ability
to generate revenue must be carefully considered.
Photovoltaic panels - Photovoltaic (PV) technology has been used on small scales to convert light
into electricity for decades, but with advancements in PV technology over the last 20 years their
use as a clean, reliable source of energy has become common. Today, PV panels annually produce
27.3 Terawatt hours worth of electricity in California, making it the second most utilized energy
source in the state. This mass implementation has also contributed to the capital cost of PV systems
dropping by approximately 34% over the last 5 years.
Preliminary cost estimates for photovoltaic systems vary based on size and design specifics , but
for the purposes of assessing the viability of implementation, a conservative cost of $3.00/watt
will be used. At this price point, assuming average electrical cost of $0.36 per kwh incurred at the
Marsh St. structure, it would take 5.7 years at 4 hours of production a day for the panels to pay for
themselves. Applying peak rates of $0.58/kwh to the analysis would be reduced this to 3.54 years.
With a lifespan for the panels of 20-30 years and minimal maintenance required to keep them
functioning efficiently, PV implementation is clearly of benefit.
Battery Walls - The last few years have also brought significant advancements in battery
technology. Often used to complement PV systems, battery walls can store solar power produced
during daylight hours, making it available for EV charging at night. A charged battery can also be
used to offset power used during peak pricing times by bridging the gap between the power output
of a PV system and the draw of high-energy equipment such as EV chargers.
At a price point of $7500 each, wall batteries require routine maintenance, and have a lifespan of
10 years or less. These units also require additional storage space that can house control systems,
as well as cooling and ventilation systems.
Although additional cost analysis would be needed in order to accurately quantify the total price
for battery wall implementation, preliminary calculations suggest this is not economically feasible.
Palm – Nipomo Design Recommendations
EV Chargers - Currently the California Green Code requires a parking structure of 200 units or
more to provide 6% of total stalls to EV charging. This requirement is high compared to other
states which highlights the commitment to environmental sustainability the City of San Luis
Obispo has shown by requiring 10% EV ready and an additional 25% capable.
It is the recommendation of City staff to implement the EV standards set forth in the City Zoning
Regulations of 10% EV ready and 25% EV capable, which is a larger implementation than required
in the California Green Code.
Photovoltaic panels – Staff recommends increasing the use of photovoltaic panels from 8,935
square feet (sf) currently being proposed to 17,147 sf. This increase requires installation of
photovoltaic panels along the perimeter of the top level of the parking structure which may change
the aesthetic look of the structure as seen from the street.
Battery wall - Battery walls are not deemed economically feasible at this time and should not be
implemented in the design of the garage.
Policy Considerations
Although this memo is focused on the capital investments associated with the proposed parking
garage, Public Works and the Office of Sustainability met to discuss additional policy
considerations that could help support staff design recommendations. It is recommended that
these policy considerations be presented at the November 5 City Council meeting and that the
issues are resourced and addressed as the construction component of the project moves forward.
The City has converging needs around rapidly increasing housing production, reducing vehicle
miles traveled, reducing congestion, supporting active transportation and transit, enhancing
downtown and implementing the downtown concept plan, addressing cost-of-living and equity
issues, and reducing greenhouse gas emissions. The Palm/Nipomo garage should exist to serve
the success of these broader policy priorities, and under this context the following policy and
operational considerations should be considered:
1. Allowing downtown residents to park and charge overnight – This could allow new
residential developments to have reduced parking requirements, would provide off-peak
charging revenue, would provide access to charging for downtown residents, and would
allow greater utilization of the garage.
2. A program to test EV charging rates – Given the dynamic pricing capabilities of
ChargePoint chargers, the existing Marsh Street and the proposed Palm/Nipomo garages
provide an opportunity to test rates to strike the correct balance between cost recovery
and utilization. Initial ideas include:
a. Equity rates that provide free or significantly reduced charging for income
qualified residents
b. Special rates for overnight charging
c. Partnership with hotels and tourism groups (e.g., TBID, Chamber of Commerce,
Downtown Association) to receive subsidies on charging rates that allow City
cost recovery and cheap charging for visitors
d. Full cost recovery for all other users
3. A program that illustrates how the project supports full implementation of the Downtown
Concept Plan. Substantial economic development opportunities exist through
implementation of the Downtown Concept Plan, including through reclaiming on-street
parking spaces for commerce and recreation and through enhancing active transportation
accessibility. An approach that allows projects to shift their EV charging space
requirements to the Palm/Nipomo garage could achieve objectives related to providing
chargers without compromising the implementation of the plan.
4. A marketing campaign to drive utilization – The existing Marsh street chargers are a
substantial investment, but they have not been supported with marketing, signage, or site
aesthetic enhancements. A collaboration with tourism and downtown organizations, as
well as with the City’s communications resources, could help drive greater utilization.
Conclusion
With uncertainty regarding the future public demand for EV charging and a bid market that is
producing much higher than anticipated construction costs, it is hard to justify increasing project
scope for infrastructures that may never be fully utilized. The electrical design recommendations
proposed by staff above was the result of weighing cost of implementation, current usage, and
future projected use of green technologies
Further implementation of the Downtown Master Plan also includes the construction of additional
parking structures and will provide new opportunities for implementing green technologies should
the cost-benefit analysis change in the future.