Energy

(U)NFV: (Un)Supervised Neural Finite Volume Methods for Solving Hyperbolic PDES

Lichtle, Nathan
Canesse, Alexi
Fu, Zhe
Matin, Hossein Nick Zinat
Maria Laura Delle Monache
Alexandre Bayen
2026

We introduce (U)NFV, a modular neural network architecture that generalizes classical finite volume (FV) methods for solving hyperbolic conservation laws. Hyperbolic partial differential equations (PDEs) are challenging to solve, particularly conservation laws whose physically relevant solutions contain shocks and discontinuities. FV methods are widely used for their mathematical properties: convergence to entropy solutions, flow conservation, or total variation diminishing, but often lack accuracy and flexibility in complex settings. Neural Finite Volume addresses these limitations by...

Defining An Accuracy Limit in Battery State Estimation

Jiang, Shida
Tao, Shengyu
Lee, Jaewoong
Scott Moura
2026

Batteries are everywhere in our daily lives. Their applications span from electronic devices to electric vehicles (EVs) and further to grid-scale energy storage systems. Accurate battery state of charge (SOC) and state of health (SOH) estimations are essential elements of a battery management system (BMS) that ensure the safe and efficient operation of various battery-powered equipment. SOC describes the remaining charge of the battery. It is defined as the ratio of the instantaneous remaining capacity to its present maximum capacity....

Hydrogen-Energy-Stations

Tim Lipman
Cameron Brooks
2006

The “hydrogen energy station” is one method of hydrogen production at small and medium scales. Unlike more conventional hydrogen station designs where hydrogen is simply delivered or produced on-site with a fuel “reformer” or water electrolyzer and then compressed and dispensed, energy stations would provide multiple functions in the same facility. They would integrate systems for production of electricity for 1) local uses and/or the utility grid, 2) re-use of thermal energy “waste heat” for building heating/cooling needs, and 3) purified hydrogen for refueling vehicles. Hydrogen energy...

An Overview of Hydrogen Production and Storage Systems with Renewable Hydrogen Case Studies

Tim Lipman
2011

Hydrogen is already widely produced and used, but it is now being considered for use as an energy carrier for stationary power and transportation markets. Approximately 10-11 million metric tonnes of hydrogen are produced in the US each year, enough to power 20-30 million cars or 5-8 million homes.1 Major current uses of the commercially produced hydrogen include oil refining (hydro-treating crude oil as part of the refining process to improve the hydrogen to carbon ratio of the fuel), food production (e.g., hydrogenation), treating metals, and producing ammonia for fertilizer and other...

Plug-In Electric Vehicles in California: Review of Current Policies, Related Emissions Reductions for 2020, and Policy Outlook

Maggie Witt
Matthew Bomberg
Tim Lipman
Brett Williams
2012

California's emissions reduction goals for criteria air pollutants (CAPs) and greenhouse gases (GHGs) have encouraged policies that support plug-in electric vehicles (PEVs). This paper explores current and planned policies that promote PEVs, potential emissions benefits from PEV adoption in California by 2020, and future policy directions. The reviewed policies include the zero-emission vehicle regulations, the low-carbon fuel standard, and the clean car standards, which all require GHG reductions. Policies prompted by the California Public Utilities Commission Alternative-Fueled Vehicle...

Strategy for Overcoming Cost Hurdles of Plug-In–Hybrid Battery in California: Integrating Post-Vehicle Secondary Use Values

Brett Williams
Tim Lipman
2010

Advances in electric drive technology, including lithium ion batteries as well as the development of strong policy drivers such as California's Global Warming Solutions Act, now contribute to a more promising market environment for the widespread introduction of plug-in vehicles in California. Nevertheless, battery costs remain high. This study explores a strategy for overcoming the significant hurdle to electric transportation fuel use presented by high battery costs. It describes offsetting plug-in-vehicle battery costs with value derived from post-vehicle stationary use of hybrid...

Fuel Cells and Hydrogen Production: Introduction

Adam Weber
Tim Lipman
2019

Hydrogen is a widely produced and used commodity, now being used as an energy carrier for stationary power and transportation markets. Tens of millions of tons of hydrogen are produced each year globally, mostly for large-scale industrial uses. As awareness grows for the need to reduce greenhouse gases and enable new energy paradigms, hydrogen is being seen as playing a critical role as shown in Fig. 1 [1]. Hydrogen provides chemical storage of electrical energy and can be efficiently converted to electricity on demand for distributed applications, thus enabling the global electrification...

Aging Diagnostics for a Commercial Sodium-ion Cell: Experimental and Simulation-based Transfer from Lithium-ion Systems

Quade, Katharina Lilith
Sauer, Dirk Uwe
Scott Moura
2025

Sodium-ion batteries are gaining attention as a cost-effective and sustainable complementary technology to their lithium counterpart. However, fully realizing their drop-in potential and integrating them into applications requires a deeper understanding of their aging behavior, as well as the implications for the overall system. A high-power, cost-sensitive application is selected, where lithium-ion cells could potentially be replaced by a cheaper complementary technology with similar power characteristics and energy density. An extensive field dataset from this application is then...

Modeling the Future California Electricity Grid and Renewable Energy Integration with Electric Vehicles

Florian Triel
Tim Lipman
2020

This study focuses on determining the impacts and potential value of unmanaged and managed uni-directional and bi-directional charging of plug-in electric vehicles (PEVs) to integrate intermittent renewable resources in California in the year 2030. The research methodology incorporates the utilization of multiple simulation tools including V2G-SIM, SWITCH, and GridSim. SWITCH is used to predict a cost-effective generation portfolio to meet the renewable electricity goals of 60% in California by 2030. PEV charging demand is predicted by incorporating mobility behavior studies and...

The CO2 Abatement Potential of California's Mid-Sized Commericial Buildings

Michael Stadler
Chris Marnay
Gonçalo Cardoso
Tim Lipman
Olivier Mégel
Srirupa Ganguly
Afzal Siddiqui
Judy Lai
2009

The Ernest Orlando Lawrence Berkeley National Laboratory (LBNL) is working with the California Energy Commission (CEC) to determine the potential role of commercial sector distributed generation (DG) with combined heat and power (CHP) capability deployment in greenhouse gas emissions (GHG) reductions. CHP applications at large industrial sites are well known, and a large share of their potential has already been harvested. In contrast, relatively little attention has been paid to the potential of medium-sized commercial buildings, i.e. ones with peak electric loads ranging from 100 kW to 5...