eothermal energy holds im-

mense potential, but its

widespread utilisation has

been hindered by past technological

limitations. However, a transforma-

tive shift is occurring with the rapid

development of Enhanced Geother-

mal Systems (EGS). These systems

offer a solution for balancing the in-

creasing inux of renewables into

the electric grid, providing baseload

power, dispatchability, and energy

storage.

By employing advanced drilling

techniques and reservoir engineer-

ing, EGS taps into the abundant heat

beneath the Earth’s surface, making

it a promising contender for meeting

future energy demands.

EGS essentially creates articial

reservoirs where hot rock exists but

lacks natural permeability or uid

saturation. Through controlled uid

injection into the subsurface, frac-

tures are created, enabling the estab-

lishment of permeability. This break-

through technology allows access to

previously untapped geothermal re-

sources, even in regions considered

inaccessible. In the transition to elec-

tric energy, EGS emerges as a reli-

able and virtually limitless energy

source, setting it apart from solar and

wind power due to its constant avail-

ability and dependability.

Driving the future innovation and

expansion of EGS is the recently

passed $369 billion US Ination Re-

duction Act (IRA). This comprehen-

sive legislation introduces a range of

incentives designed to encourage in-

vestment in zero-emission technolo-

gies in the United States. The IRA

includes an investment tax credit

(ITC) of 30 per cent that went into

effect in January 2023. Additionally,

there are stackable bonus credits, al-

lowing monetisation of up to 70 per

cent of project costs, including a 20

per cent bonus for projects deployed

in low-income underserved areas.

The signicant support provided by

this historic legislation, through

monumental federal tax incentives,

will attract private sector capital for

the development and deployment of

innovative technologies, accelerating

the energy transition.

Energy & Sustainability Expert

Mike Matson of the Boston Consult-

ing Group explained: “EGS offers a

more favorable Levelised Cost of

Energy (LCOE) compared to other

conventional and renewable energy

sources when the IRA tax credits are

included. As shown in the chart cre-

ated by the Boston Consulting

Group, the LCOE for onshore wind,

after tax credits, is estimated at $15,

but it would require an additional

$110 for storage, making it more

than double the LCOE of EGS for

providing reliable electricity.”

California, a leading force in re-

newable energy, exemplies the in-

creasing urgency for energy storage.

As the state’s solar and wind power

generation grows, there is a critical

need for affordable and effective en-

ergy storage technologies to balance

utility loads. With high electricity

rates and a signicant portion of en-

ergy imports, California may require

up to 14 GW of energy storage by

2025 to maintain a reliable grid.

In this context, pumped storage

emerges as a clean, scalable, and

sustainable solution, outperforming

battery storage limitations. While

batteries typically provide backup

power for only a few hours and have

a restricted lifetime due to limited

charging cycles, pumped storage of-

fers longer-term storage capabilities.

Additionally, the reliance on lithium

batteries exacerbates material and

mineral shortages and poses chal-

lenges for disposal.

Aquifer Pumped Storage (APS), a

concept developed by researchers at

the University of Colorado-Boulder

(UC-B) in 2007, offers a promising

energy storage and electricity gener-

ation solution.

APS utilises a reciprocal pump-

turbine unit located in an aquifer, si-

multaneously pumping water to the

surface reservoir and generating

electricity as the released water

ows through the turbine. By cou-

pling APS with renewable genera-

tion sources such as wind turbines

or solar panels, energy can be

stored in the form of gravitational

potential energy. The ability to gen-

erate electricity from stored water

provides an effective means of bal-

ancing the grid and meeting energy

demands. While APS was not com-

mercialised at the time due to limit-

ed demand for energy storage, the

current landscape, supported by the

IRA’s funding and tax credits, pro-

vides an opportunity for further de-

velopment and deployment.

Regenbiomass is at the forefront of

developing Timber & Carbon Farms

in California and Africa. Our mis-

sion is to produce regenerative lum-

ber and facilitate decarbonisation

through afforestation. In 2022, the

company embarked on a pilot proj-

ect that showcased the potential of

our vision. By growing 800 paulow-

nia trees on marginal land in the des-

ert of Southern California, we not

only demonstrated the viability of

our approach but also received vital

funding through a USDA grant.

It was during this project that we

stumbled upon the concept of aqui-

fer pumped storage, a remarkable

discovery that led us to delve deeper

into the emerging EGS industry and

its connection to the timely IRA tax

benets.

The alarming statistics surrounding

deforestation and electricity depriva-

tion in Africa highlight the urgency

of our work. Among the ten coun-

tries worldwide with the largest an-

nual net loss of forested area, six are

in Africa, which sadly witnesses an

average loss of 40 000 km

of forests

each year. Furthermore, with a popu-

lation of approximately 1.2 billion,

half of Africa’s inhabitants are de-

prived of electricity, hindering prog-

ress and development.

However, amidst these challenges

lies a glimmer of hope and the nexus

with aquifer pumped storage. Many

of the poorest African nations are

blessed with abundant underground

aquifers, which hold vast reserves of

freshwater. These aquifers present

not only a potential solution for irri-

gation, afforestation, and access to

clean water but also offer an oppor-

tunity for generating renewable elec-

tric power. By tapping into these hid-

den treasures, we can transform the

lives of communities and contribute

to sustainable development.

Africa, with its growing population

and abundant natural resources, is

poised to shape the global energy

transition. By 2050, Africa’s popula-

tion is projected to reach 2.5 billion

and its combined business and con-

sumer spending to exceed $16 tril-

lion. The continent’s vast reserves of

precious metals and hydrocarbons,

coupled with its untapped solar,

wind, and hydroelectric potential,

position Africa as a key player in

driving renewable energy solutions.

To unlock its full potential, energy

storage becomes crucial.

The Sahel region of Africa, known

for its arid climate, also holds vast

underground treasures. Massive

aquifers beneath the surface provide

potential solutions to water scarcity

in the region. Moreover, the Sahel

region exhibits signicant geother-

mal potential, offering a clean and

sustainable energy source. Pilot proj-

ects are currently underway to vali-

date the utilisation of geothermal

power generation alongside agricul-

tural irrigation from aquifers. Col-

laboration among geologists, hydrol-

ogists, and thermodynamic experts is

essential in exploring the potential of

harnessing the “heat beneath our

feet” to support the global energy

transition.

Enhanced Geothermal Systems of-

fer a promising solution to meet the

increasing energy needs of the fu-

ture. With advanced drilling tech-

niques and reservoir engineering,

EGS has the potential to tap into pre-

viously untapped geothermal re-

sources, providing a reliable and un-

interrupted power supply. Supported

by the Ination Reduction Act (IRA)

and federal tax incentives, the devel-

opment and deployment of EGS are

expected to accelerate, offering a

low cost of energy compared to oth-

er conventional and renewable

sources.

Additionally, pumped storage, such

as Aquifer Pumped Storage, presents

a clean and sustainable solution for

energy storage, complementing the

intermittent nature of renewable en-

ergy sources. Africa, with its young

and growing population, abundant

natural resources, and immense po-

tential for renewable energy, holds

the key to shaping the global energy

landscape.

By harnessing geothermal energy

and exploring aquifer-based solu-

tions, the continent can drive the

transition to a renewable energy fu-

ture while addressing water scarcity

challenges. The synergy between

geothermal energy and aquifer utili-

sation presents a unique opportunity

to propel Africa towards sustainable

development and position it as a

leading player in the global energy

transition.

Phil Cruver is President at Calor-

nia-based company RegenBiomass.

With the global focus on renewable energy, Enhanced Geothermal Systems (EGS) can take centre-stage as

the ideal solution for base load power, dispatchability and energy storage. RegenBiomass’ Phil Cruver explains

how the synergy between EGS and a technology known as Aquifer Pumped Storage could be the ideal solution

for supporting the global energy transition, especially in arid parts of Africa.

Taking the clean energy

transition underground

THE ENERGY INDUSTRY TIMES - JULY 2023

Technology Focus

LCOE for onshore wind, after

tax credits, is estimated at

$15, but it would require an

additional $110 for storage,

making it more than double

the LCOE of EGS for providing

reliable electricity