As I mentioned in my previous post, I did some digging and got some more information about that interesting "Hybrid Boat" I saw when I was walking along the piers in San Francisco. Here are some more specifics:
Previously used as a commercial diving boat, the Hornblower Hybrid is a 64ft catamaran with a fully-enclosed main deck and a covered roof deck. The boat, which has a capacity of 149 passengers, underwent retrofitting, repowering, and refurbishing in Sausalito to be more energy-efficient and environmentally friendly. The boat was originally put into service as a dive platform in the Gulf... then purchased and moved to Sausalito for its most recent transformation.
Most noticeable about the boat are the twin 10ft-tall wind turbines (1.2 KW normal output, 2.0 KW max.) and a photovoltaic solar array (1.2 KW) covering the awning on the top deck. These two features (turbines and PV array) provide energy that is stored in battery banks that power the navigation tools, lighting, and other electronics on the boat. Excess power is stored in the main propulsion battery banks.
For propulsion, the boat uses two Series 60 MTU Tier 2 marine diesel engines that are fuel-efficient and cleaner, thus reducing the amount of diesel fuel required and reducing emissions. These diesel engines are run two Marathon 320 KW generators that send the power to two Yosukawa variable frequency drives that control the output of two 400 horsepower electric motors connected directly to conventional propellers. This customized drive system allows the captain to monitor the boat's energy needs and select the most efficient power sources (for example, when the boat is idle at the dock, the engines shut down and the motors run off energy stored in the battery banks). A 380V DC battery bank allows a "zero-emission mode" to be used.
Lighting throughout the boat is Light-Emitting-Diode (LED), which requires a fraction of the energy required by standard bulbs to provide equal or more illumination. The LEDs also require less maintenance time and trouble.
This boat was purchased, refurbished, and put into service by Hornblower's Alcatraz Cruises--no grant or public money was used in the boat's redesign and refurbishment.
Hornblower's Alcatraz Cruise on the Hybrid website has a description of the service that this craft is being used for and also has an Excellent Diagram Showing the Basic Schematics of the Hybrid Vessel.
You can see this interesting vessel in person at the Alcatraz Landing at Pier 33 in San Francisco, CA.