Energy in Ancient Greece

Summary: Ancient Greece largely relied on traditional energy sources, such as human and animal power, in addition to the primary energy sources of solar energy, hydropower, and wind power.

Ancient Greek civilization has an important place in the history of energy as an early civilization with a scientific interest in the phenomenon of energy. The word energy comes from the ancient Greek word energeia, meaning “activity,” as it appeared in the work of Aristotle in 4th century b.c.e., although Aristotle’s concept of energy was much different from the modern understanding of the term. Ancient Greek civilization took root in Greece and in the surrounding areas of Mediterranean beginning with the Helladic civilization (2800–1550 b.c.e.) in mainland Greece, the Cycladic civilization of the Aegean Sea (3300–2000 b.c.e.), and the Minoan civilization in Crete (3650–1170 b.c.e.). Subsequently, Mycenaean civilization (1600–1100 b.c.e.) in mainland Greece enjoyed a wide array of cultural exchanges with other Bronze Age centers. After the Mycenaeans, a period known as Greek Dark Ages took place until the formation of ancient Greek city-states in the 9th and 8th centuries b.c.e. During this period, a number of ancient Greek colonies appeared on the Black Sea, in southern Italy, and in Asia Minor. The Archaic period (750–490 b.c.e.), Classical period (490–323 b.c.e.), and Hellenistic period (323–146 b.c.e.) followed, and Greece was annexed to the Roman Empire in 146 b.c.e.

Geography and Environment

It is hard to define the geography of Ancient Greece, given the vast extent of Greek civilization by the Classical period. Generally, the region was characterized by a Mediterranean climatic regime, with hot and dry summers and damp and mild winters. Precipitation levels fluctuated between droughts and heavy storms.

The Greek mainland, a peninsula, was surrounded by the Ionian Sea to the west, the Aegean Sea to the east, and the Mediterranean to the south. The mainland is characterized by a rocky, hilly, and mountainous topography, especially toward the southern part of the peninsula. The mountainous landscape was an important factor in the establishment of numerous city-states early in the ancient Greek history. Additionally, this type of geography made it hard to travel inland, leading to early development of sea-traveling technologies.

The boundary between Macedon and Greece was set by Mount Olympos to the north. Furthermore, the Pindus mountain chain divides Greece in a north-south alignment in the west south to the Gulf of Corinth. To the east of this range, other mountains dominate the mainland topography from the north to south, some of the main peaks including Mount Ossa, Mount Pelion, Mount Othrys, Mount Parnassos, Mount Helikon, and Mount Parnes. Mountains in ancient Greece were likely very important, as they provided a number of biomass resources used as energy by the inhabitants of the peninsula. It is known that when the resources of the mainland were exhausted, ancient Greeks used timber from adjacent regions, including Macedon, Cyprus, and Asia Minor.

Generally, the majority of the large trees were found in regions to the north of mainland Greece, and much of Greece was covered with Mediterranean vegetation. Olive trees were especially important. Aside from providing wood for burning, the fruit of these trees was used to produce olive oil. Olive oil consumption was an important source of energy, both in the Greeks’ diet and as fuel for lamps. Furthermore, the rocky terrain of the Greek peninsula was conducive to raising herds of sheep and goats. Thus, human caloric intake from dairy products and meat largely came from these animals rather than cattle.

Additional Greek settlements, especially those in Asia Minor, enjoyed flatter landscapes. The physiography of Asia Minor in particular allowed increased agricultural activity and provided pastureland for cattle. Large trees were also present in Asia Minor along with certain types of metals. For example, iron was more abundant in Asia Minor than in mainland Greece. Cyprus, an island in the middle of the eastern Mediterranean Sea, was also a source of metals for mainland Greece, including copper.

The Greek mainland, as well as the surrounding islands, such as Crete, were also rich in clay, leading to the large-scale production of pottery. Pottery manufacturing became an important industry in terms of energy use, as its production required considerable biomass energy.

Religion and Forms of Energy

Ancient Greeks were aware of the importance of different types of energy in their daily lives. They used mythology to express their understanding of different forms of energy, as they did not have the necessary scientific tools to make sense of the natural phenomena they observed. Ancient Greeks were interested in the root causes of droughts, earthquakes, electrical storms, eclipses, floods, plagues, and tidal waves. The primary energy sources they observed in the natural realm carried magical meanings for them. As a result, ancient Greek society created a variety of mythological personae identified with energy sources. In the Greek mythology, the phenomenon of sound energy was identified with the goddess Echo. Sound is the transmission of energy through sound waves. Heat, a form of energy related to the motion of atoms or molecules and transmitted through conduction, convection, and radiation through fire, was associated with Prometheus. According to Greek myth, Prometheus was the first god to introduce fire to humans, which he stole from the god Zeus and gave to humans. Hephaestus was also identified with fire, particularly volcanoes, and was the patron god of technology, blacksmiths, craftsmen, and metallurgy—all activities that require considerable energy resources (both human and biomass) to conduct.

The goddesses Demeter and Persephone were responsible for harvest, growth, and vegetation in connection with seasons (they were among the Horae, goddesses of the seasons and natural time). Seasons, local weather, regional climates, and agriculture had links with solar power as common denominator of all of these phenomena. The mythological figure Helios, a Titan god, represented the sun in Greek mythology. Helios was imagined to drive a chariot across the sky each day to the land of the Hesperides (evenings) in the west and return to his rising place in the east. As ancient Greeks would have observed, Helios’s daily routine would allow solar power to be converted to light and thermal energy, providing them with the favorable existence they enjoyed in the sunlit landscapes of the Mediterranean. In this context, the son of Zeus and Leto, Apollo, the god of light and sun, was also important. Apollo, during 3rd century b.c.e., began to be identified with Helios, as Apollo Helios. Finally, ancient Greeks attributed events relevant to skies, including atmospheric phenomena, to the father of gods and men, Zeus. Zeus was the god of sky and thunder and could use thunderbolts or lightning (electricity) to punish his subjects. Poseidon, Zeus’s brother, was responsible for the seas and was also associated with earthquakes as the Earth Shaker.

Thus, the archaeological record reveals that the gods and goddesses in Greek mythology were representatives of natural phenomena and energy sources. Greeks explained certain forms of energy via natural events that were influential and vital to their lives, ascribing supernatural powers to their gods in their representation of energy forms.

Energy in Ancient Greek Writing

The ancient Greeks were careful observers of their environment. Mention of electricity can be found as early as the 6th century b.c.e. The Greek philosopher Thales of Miletus is known to have observed static electricity, because it is reported that when he polished a piece of amber with a cloth probably made of wool or fur, he generated a static charge that caused some materials such as a straw or feather to stick to the amber.

In his writings, Aristotle used the words energeia (literally, “being at work”) and entelechia (“being at an end”). The word kinesis, which can be translated as movement or motion, was additionally described as a form of energeia. Aristotle also used the word energeia to denote pleasure and happiness. It appears that he had a sense of what energy was, but he did not discuss the concept of energy as it is viewed today.

Human and Animal Power

Ancient Greeks’ energy needs were met largely by human muscular power. The society expended significant amounts of human labor on agriculture, construction, and manufacturing. Most of the labor was done by agrarian, underprivileged, or slave populations. From the point of view of the elites, labor, or working for one’s livelihood, was not viewed as inherently good; in fact, the word ponos, meaning “hard physical toil,” carried a negative connotation. Nonetheless, the douloi (meaning “slaves” or “the unfree”) played a key role in ancient Greek culture as laborers. Slaves participated in shield making, silver mining, temple building, pottery making, textile weaving (for nondomestic purposes), and winemaking (for export). Aristotle viewed the energy expended by slave labor to be necessary so that citizens could focus on civic life in the polis (city-state). By the 5th century b.c.e., slaves in certain city-states constituted as much as a third of the total city population.

There were four primary sources of slaves in the ancient Greek society: through hostage taking during war, piracy, banditry on land, and the international slave trade. Household slaves, frequently women, helped with cleaning, cooking, weaving, raising children, and other domestic chores. Male slaves worked as potters, metalworkers, farmers, construction workers, and miners in quarries or metal mines. Also, certain slaves belonged to city-states and temples instead of individual citizens. They performed a variety of specialized tasks. Taken as a whole, slaves were an important facet of the ancient Greek economy as an important energy source.

Overall, ancient Greece had a rural and agrarian economic base. Like ancient Mesopotamian societies, ancient Greek society enjoyed a variety of food crops and animal products. During farming activities, the Greeks used certain instruments for the redirection of muscular power. Most important were the plow (harnessing animal power), hoe and spade (both tools used in tillage), threshing boards and winnowing baskets (allowing grain to be separated from stems and lighter particles), and sickles (for harvesting). Irrigation tools included the lever, the wedge, the windlass, and the pulley, believed to be imported from the East.

Animal power was another important source of energy harnessed by the ancient Greeks. Oxen were used as draft animals in the fields; donkeys and mules were commonly used in mills. Donkeys and mules were also important pack animals, transporting goods through the mountainous terrain of ancient Greece.

Biomass Energy Sources

Practically all cooking, home heating, lighting, construction, shipbuilding, and metallurgy necessitated the burning of biomass resources. Ancient Greeks acquired biomass from their environment, and wood was the most important. Classical writers mention large-scale deforestation near cities and mining districts, as well as in more isolated locations. By the 5th century b.c.e., the area surrounding Athens was mostly deforested. Textual evidence shows that by Hellenistic times Athens had to rely on forests north of the Greek peninsula and in other parts of the Mediterranean. Detailed price lists that survive from the era record the increasing cost of fuelwood as well as fine woods. Additional textual evidence reveals the importance of fuelwood, as it was listed as a form of payment to Athenian public servants along with other staple items, such as bread and opson (the complement to the staple portion of a meal, often fish or fruit).

Charcoal production from timber, used for metal smelting and refining, explains much of the deforestation. Charcoal-making involved laborious processes and the extensive use of natural resources. For example, as early as the Bronze Age, copper processing in Cyprus (a trading partner of Mycenae) led to massive deforestation. It was calculated that to produce 1 ingot (29 kilograms) of copper, 6 tons of charcoal were needed, or 125 pine trees (which would have covered an area constituting approximately 4 acres). Iron became more popular than copper after the Bronze Age. Copper melts at 1,084 degrees Celsius, whereas iron melts at the much higher temperature of 1,535 degrees Celsius. Iron metallurgy required massive amounts of charcoal use, even more than copper metallurgy. Metallurgy was therefore an essential component of ancient Greek industry and necessitated considerable biomass to produce the energy required to maintain it.

Solar Power

By the 5th century b.c.e., Greeks faced serious energy shortages. One of the ways they dealt with the problem was to use solar energy in a more practical manner. Archaeological and textual evidence shows that by 5th century b.c.e., architectural planning of Greek houses had evolved to take advantage of the sun in different seasons. From Aristotle’s writings we know that houses were designed to take cold winter winds into consideration by protecting the northern section of houses. Socrates noted the advantage of houses that faced south, which kept the house warm. The famous tragedian Aeschylus believed that only primitives and barbarians would be so ignorant as to build their houses without taking advantage of sunshine during the winter months. Orthogonal city planning in ancient Greece and in Asia Minor in Greek cities such as Colophon, Olynthus, and Priene demonstrate the importance placed on orienting houses in an east-west and north-south direction to use the sun’s thermal properties.

In other uses of solar power, the Greeks used concave reflectors to concentrate the sun’s radiation in order to light fires for cooking; these devices may also have played a role during rituals in religious spaces. These handheld concave mirrors, made out of polished brass, are known as burning mirrors in today’s literature. Burning mirrors, in Plutarch’s words “draw down from the skies the pure and unpolluted flame from sunbeams.” These devices worked by directing focused sunlight into dry biomass, such as straw and other kindling. The Greek mathematician Archimedes (based on the writings of 2nd century c.e. author Lucian and 7th century c.e. author Anthemius of Tralles) was famous for his supposed use of a similar device that could direct sunlight to start fires aboard enemy ships.

Prior to Archimedes, Dositheus described the function of parabolic mirrors that, through reflection, could generate higher temperatures than basic spherical mirrors. Dositheus is believed to have built the first parabolic mirror, a century prior to the Siege of Syracuse (212 b.c.e.), during which Archimedes’s device was supposedly used against Roman ships. Archimedes’s fame for using devices that harnessed sunbeams to burn enemy ships was considered a myth until an experiment conducted by students at the Massachusetts Institute of Technology (MIT) proved that it might be feasible (if not a weapon of choice for practical reasons). The MIT experiment showed that on a cloudless day, using numerous mirrors, people onshore could have induced burning on a ship that was not moving. The exposed wood surface on the model ship used in the experiment started to give off smoke, an indication that the carbon in the wood was burning with a surface temperature of at least 705 degrees Fahrenheit.

Wind and Hydro Power

Besides solar power, wind and hydropower were harnessed by ancient Greeks to a certain extent, especially during their seafaring journeys. The Mediterranean’s climate and winds were important for ancient Greek sailing. Even though Mediterranean regions were subjected to strong winds and stormy weather, the daily and annual patterns of winds and weather, particularly during the summer months, were also fairly dependable.

The Greeks were also knowledgeable about sea currents, prevailing winds, and associated wave formations in the Ionian, Aegean, and Black Seas, allowing them to harness the energy of these winds and hydropower to move their ships. Both merchant vessels and warships were equipped with sails made out of linen (mostly from flax or Egyptian cotton). Their ships were also equipped with oars to enable propulsion by means of manpower when wind power was not feasible. Some ships contained 50 oarsmen, and for short intervals they could provide a power input of up to 7 kilowatts. Bigger ships, such as classical warships, could have 170 rowers and produce more than 20 kilowatts, traveling nearly 12 miles (20 kilometers) per hour. Whereas warships used oarsmen for the most part, heavier merchant ships relied on wind and their sails for speed.

Finally, hydropower was used by ancient Greeks as early as 2000 b.c.e. to harness the force of rivers via waterwheels. The power was put to work pressing grapes for wine and grinding grain to make flour for bread. The root hydro comes from the Greek word for water or liquid.

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