Algae as Bio-Cell with Zero Emission Next Generation Energy Source

Abstract

Traditional batteries demand a lot of energy to maintain and constantly need recharging. Once discarded, the heavy metals and chemical solutions inside them can leach out and poison the environment. With roughly 745 million batteries thrown away every year, they add a massive amount of unnecessary waste to our landfills. Because energy production remains a leading driver of climate change, this project explores a greener solution: biological photovoltaic batteries (bpvs) that harness microbial photosynthesis to stay charged .based on current research, algae can serve as the core biological component for a bpv. The main goal of this project is to cut down on battery waste while creating longer-lasting, sustainable power sources. Specifically, using algae for this purpose helps tackle environmental issues by giving harvested algae a productive use, which can help prevent harmful algal blooms.

Introduction

A Sustainable Alternative to Conventional Batteries

The project focuses on developing biophotovoltaic (BPV) batteries using algae as an eco-friendly and rechargeable alternative to conventional chemical batteries. Traditional batteries contribute to environmental pollution because their harmful chemicals can leak into the soil and water when disposed of improperly. Algae-based batteries offer a potential solution by generating electricity through photosynthesis while helping capture carbon dioxide.

1. Introduction and Background

Algae produce oxygen and release electrons during photosynthesis. Biophotovoltaic technology captures some of these electrons to generate a small electrical current.

Researchers at the University of Cambridge have developed biocells that use living algae to produce electricity continuously, even in darkness for some time. This technology could reduce dependence on disposable chemical batteries and provide a more sustainable energy source.

2. Research Framework and Hypothesis

The main research question is: Which algae species and light wavelength produce the highest electrical power?

Two hypotheses were proposed:

• Hypothesis 1: Spirulina algae would produce higher power than Nannochloropsis because of its adaptability to high-pH saltwater environments.

• Hypothesis 2: Blue light would produce the highest power because it supports photosynthesis in algae.

The project investigates how algae species and different light wavelengths affect battery performance.

3. Experimental Design and Methodology

A total of 16 biophotovoltaic batteries were constructed using:

• Copper and zinc electrodes.

• Saltwater solution.

• Two algae species: Spirulina and Nannochloropsis.

• Coloured light filters: Red, yellow, and blue.

• Blank control batteries without algae.

Copper wires were shaped into springs, and metal electrodes were cleaned and sanded before use. Equal quantities of water, salt, and algae were maintained to ensure consistency.

4. Data Collection and Controlled Variables

The batteries were tested over two days using:

• pH sensor to measure acidity or alkalinity.

• Ammeter to measure electrical current.

• Voltmeter to measure voltage.

• LabQuest to record experimental data.

Three trials were conducted for each setup. The quantities of algae, saltwater, electrode materials, and measurement times were kept consistent to improve experimental reliability.

5. Results and Discussion

A. Comparison of algae species

Spirulina batteries produced higher average power than Nannochloropsis batteries.

Hypothesis 1 supported

This suggests that Spirulina was more effective under the experimental conditions.

B. Effect of light wavelength

• Spirulina produced its highest power under blue light.

• Nannochloropsis produced its highest power under yellow light.

Hypothesis 2 partially rejected

Therefore, the best-performing wavelength depended on the algae species.

6. Voltage, Battery Life, and pH Analysis

• Voltage: The blank control battery recorded the highest raw voltage. However, among algae-based batteries, yellow-filtered setups produced the highest voltage for both algae species.

• Battery life: Electrical output fluctuated over time, with some algae batteries increasing in power while others decreased.

• pH relationship: Lower pH generally corresponded to higher voltage, although some exceptions were observed. Yellow-filtered Spirulina showed both the lowest pH and highest voltage among the algae batteries.

References

[1] Bhatt, A et al. (2016). How a battery works. Australian Academy of Science. [2] Bombelli, P. (2018, January 10). Harnessing the power of algae: new, greener fuel cells move step closer to reality. University of Cambridge. [3] Driver, A, & Bombelli, P. (2018) Biophotovoltaics Energy From Algae. University of Cambridge. [4] Everything You Need To Know About Battery Recycling. (2022, April 1). GarbageDay. [5] Electric Circuits: Basics of the voltage and current laws. (2015, June 12). [Video]. YouTube. [6] Electric Potential: Visualizing Voltage with 3D animations. (2015, June 3). [Video]. YouTube. [7] Guo, Y.H (2021). A Novel Approach to Decomposing Polystyrene. Canada-Wide Science Fair 5-page Report. [8] Huang, A.; Sun, L.; Wu, S.; Liu, C.; Zhao, P.; Xie, X.; Wang, G.( 2016) Utilization of Glucose and Acetate by Chlorella and the Effect of Multiple Factors on Cell Composition. J. Appl. Phycol., 29, 23–33. [9] Making a battery with a zinc plate, copper plate and salt water. (2020, April 1). [Video]. YouTube. https://www.youtube.com/watch?v=_IcnnXtaQ1c [10] Sharkey, T et al. n.d. Alternative Energy - Biological photovoltaics. Swiss Environmental Technology AG. [11] Technology Networks. (2022, February 21). Paired vs Unpaired T-Test: Dif erences, Assumptions and Hypotheses. Informatics from Technology Networks. [12] Tschortner, J et al. (2019). Biophotovoltaics: Green Power Generation From Sunlight and Water. frontiers in Microbiology. [13] Woodford C. (2021) Batteries. Explain that Stuff. [14] Wey, L. (2019) The Development of Biophotovoltaic Systems for Power Generation and Biological Analysis. Chemistry Europe.

Copyright

Copyright © 2026 Hiren V. Makwana, Dr. Mita J. Vakilwala. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.